The Back-and-Forth Sequence Imagine a path made up of &lt; and &gt; and ending in a @, e.g.

&gt;&lt;&gt;@


A walker starts on the left-most cell. He will traverse the path as follows:


If the walker is on a @ cell, he's reached the goal and is done.
If the walker is on a &gt; cell, the entire path shifts one step to the right, cyclically, taking the walker with it.
If the walker is on a &lt; cell, the entire path shifts one step to the left, cyclically, taking the walker with it.
Afterwards, the walker takes a single step. If he's at either end of the path, he moves away from the end. Otherwise he keeps moving in the direction he moved on the last step (ignoring the rotation), walking right initially.


Let's work through the above example. The walker's position is marked with ^:

&gt;&lt;&gt;@   --rotate--&gt;  @&gt;&lt;&gt;
^                    ^
step right (first step):
@&gt;&lt;&gt;   --rotate--&gt;  &gt;&lt;&gt;@
  ^                  ^
step right:
&gt;&lt;&gt;@   --rotate--&gt;  @&gt;&lt;&gt;
  ^                    ^
step left (dead end):
@&gt;&lt;&gt;   --rotate--&gt;  &gt;&lt;&gt;@
  ^                  ^
step left:
&gt;&lt;&gt;@   --rotate--&gt;  @&gt;&lt;&gt;
^                    ^
step left:
@&gt;&lt;&gt;   Goal reached!
^


The walker visited 6 cells in the process (including the starting cell as well as the @, and counting each cell as often as it's visited).

Here is a small example, where the walker is transported across the edges by a rotation:

&gt;&gt;@   --rotate--&gt;  @&gt;&gt;
^                   ^
step right (first step):
@&gt;&gt;   --rotate--&gt;  &gt;@&gt;
  ^                ^
step right (dead end):
&gt;@&gt;   Goal reached!
 ^


This time the walker visited 3 cells.

We can easily turn this into an integer sequence:


You're given a positive integer N, e.g. 9.
You compute the the binary representation of this integer, e.g. 1001.
Then turn 1 into &gt; and 0 into &lt; and append a @: &gt;&lt;&lt;&gt;@.
We associate with N the number of cells visited by the walker in the number constructed this way.


The first few elements of the resulting sequence are:

2, 3, 3, 4, 6, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 6, 6,
6, 10, 6, 10, 8, 8, 6, 10, 8, 8, 6, 6, 6, 6, 7, 7


This may seem quite arbitrary, but the resulting sequence actually turns out to have a lot of structure:



For reference, you can find the first 2048 numbers of the sequence in this pastebin.

The Challenge

You guessed it: you're to compute the above sequence. You can do that one of three ways:


You can produce an infinite sequence (while memory permits), either by continuously outputting (separated by non-numeric characters) values or by using some form of infinite generator in languages that support them. If you print an infinite stream to STDOUT, you don't have to print the numbers one by one, but make sure that every number would be printed after a finite amount of time (and in order). If you use this option, you should not take any input.
You can take an integer N as input and produce the Nth term of the sequence.
You can take an integer N as input and produce everything up to the Nth term of the sequence, either as a list or string using an unambiguous separator.


Since I don't want to penalise languages which can't easily convert between bases, instead of the integer N you may instead take the binary representation of N, using 0s and 1s as usual (as a list or string), with the most-significant bit first.

You may write a program or function, taking input via STDIN (or closest alternative), command-line argument or function argument and outputting the result via STDOUT (or closest alternative), function return value or function (out) parameter.

Standard code-golf rules apply.

Background

This actually computes the number of "ticks" a straight-forward interpreter of my esoteric programming language Labyrinth would need to interpret the "path" as source code. In that case, the "walker" is simply the instruction pointer (which has a position and a direction), the @ command terminates the program and &lt; and &gt; are source-code modification commands.
Matlab (score=230,n=inf)

function w(s,f),b=[];e=0;for i=s:f,a=dec2bin(i);c=find(a=='1');g=numel(a)+1;if numel(c)&gt;=g/2;if mod(g,2)==1,fprintf('%d ',g);else,d=c(g/2);fprintf('%d ',2*d);end,else,fprintf('%d ',g);end,e=e+1;if(e==100),e=0;fprintf('\n');end;end



The function takes s as starting index and f as ending (type inf if you want to keep on to infinite).
The function can go forever without any remarkable time-lag between any two outputs type h=1000000000000000000000000000000000000000000000000000;w(h,h+1) to make sure.
The algorithm follows a mathematical approach that i will explain later, and it does confirm Martin's referenced list, basing on this program:

stored=[2, 3, 3, 4, 6, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 6, 6, 6, 10, 6, 10, 8, 8, 6, 10, 8, 8, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 8, 8, 8, 8, 8, 8, 8, 14, 8, 8, 8, 14, 8, 14, 12, 12, 8, 8, 8, 14, 8, 14, 12, 12, 8, 14, 12, 12, 10, 10, 10, 10, 8, 8, 8, 14, 8, 14, 12, 12, 8, 14, 12, 12, 10, 10, 10, 10, 8, 14, 12, 12, 10, 10, 10, 10, 8, 8, 8, 8, 8, 8, 8, 8, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 18, 10, 10, 10, 10, 10, 10, 10, 18, 10, 10, 10, 18, 10, 18, 16, 16, 10, 10, 10, 10, 10, 10, 10, 18, 10, 10, 10, 18, 10, 18, 16, 16, 10, 10, 10, 18, 10, 18, 16, 16, 10, 18, 16, 16, 14, 14, 14, 14, 10, 10, 10, 10, 10, 10, 10, 18, 10, 10, 10, 18, 10, 18, 16, 16, 10, 10, 10, 18, 10, 18, 16, 16, 10, 18, 16, 16, 14, 14, 14, 14, 10, 10, 10, 18, 10, 18, 16, 16, 10, 18, 16, 16, 14, 14, 14, 14, 10, 18, 16, 16, 14, 14, 14, 14, 12, 12, 12, 12, 12, 12, 12, 12, 10, 10, 10, 10, 10, 10, 10, 18, 10, 10, 10, 18, 10, 18, 16, 16, 10, 10, 10, 18, 10, 18, 16, 16, 10, 18, 16, 16, 14, 14, 14, 14, 10, 10, 10, 18, 10, 18, 16, 16, 10, 18, 16, 16, 14, 14, 14, 14, 10, 18, 16, 16, 14, 14, 14, 14, 12, 12, 12, 12, 12, 12, 12, 12, 10, 10, 10, 18, 10, 18, 16, 16, 10, 18, 16, 16, 14, 14, 14, 14, 10, 18, 16, 16, 14, 14, 14, 14, 12, 12, 12, 12, 12, 12, 12, 12, 10, 18, 16, 16, 14, 14, 14, 14, 12, 12, 12, 12, 12, 12, 12, 12, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 22, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 22, 12, 12, 12, 12, 12, 12, 12, 22, 12, 12, 12, 22, 12, 22, 20, 20, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 22, 12, 12, 12, 12, 12, 12, 12, 22, 12, 12, 12, 22, 12, 22, 20, 20, 12, 12, 12, 12, 12, 12, 12, 22, 12, 12, 12, 22, 12, 22, 20, 20, 12, 12, 12, 22, 12, 22, 20, 20, 12, 22, 20, 20, 18, 18, 18, 18, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 22, 12, 12, 12, 12, 12, 12, 12, 22, 12, 12, 12, 22, 12, 22, 20, 20, 12, 12, 12, 12, 12, 12, 12, 22, 12, 12, 12, 22, 12, 22, 20, 20, 12, 12, 12, 22, 12, 22, 20, 20, 12, 22, 20, 20, 18, 18, 18, 18, 12, 12, 12, 12, 12, 12, 12, 22, 12, 12, 12, 22, 12, 22, 20, 20, 12, 12, 12, 22, 12, 22, 20, 20, 12, 22, 20, 20, 18, 18, 18, 18, 12, 12, 12, 22, 12, 22, 20, 20, 12, 22, 20, 20, 18, 18, 18, 18, 12, 22, 20, 20, 18, 18, 18, 18, 16, 16, 16, 16, 16, 16, 16, 16, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 22, 12, 12, 12, 12, 12, 12, 12, 22, 12, 12, 12, 22, 12, 22, 20, 20, 12, 12, 12, 12, 12, 12, 12, 22, 12, 12, 12, 22, 12, 22, 20, 20, 12, 12, 12, 22, 12, 22, 20, 20, 12, 22, 20, 20, 18, 18, 18, 18, 12, 12, 12, 12, 12, 12, 12, 22, 12, 12, 12, 22, 12, 22, 20, 20, 12, 12, 12, 22, 12, 22, 20, 20, 12, 22, 20, 20, 18, 18, 18, 18, 12, 12, 12, 22, 12, 22, 20, 20, 12, 22, 20, 20, 18, 18, 18, 18, 12, 22, 20, 20, 18, 18, 18, 18, 16, 16, 16, 16, 16, 16, 16, 16, 12, 12, 12, 12, 12, 12, 12, 22, 12, 12, 12, 22, 12, 22, 20, 20, 12, 12, 12, 22, 12, 22, 20, 20, 12, 22, 20, 20, 18, 18, 18, 18, 12, 12, 12, 22, 12, 22, 20, 20, 12, 22, 20, 20, 18, 18, 18, 18, 12, 22, 20, 20, 18, 18, 18, 18, 16, 16, 16, 16, 16, 16, 16, 16, 12, 12, 12, 22, 12, 22, 20, 20, 12, 22, 20, 20, 18, 18, 18, 18, 12, 22, 20, 20, 18, 18, 18, 18, 16, 16, 16, 16, 16, 16, 16, 16, 12, 22, 20, 20, 18, 18, 18, 18, 16, 16, 16, 16, 16, 16, 16, 16, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 22, 12, 12, 12, 12, 12, 12, 12, 22, 12, 12, 12, 22, 12, 22, 20, 20, 12, 12, 12, 12, 12, 12, 12, 22, 12, 12, 12, 22, 12, 22, 20, 20, 12, 12, 12, 22, 12, 22, 20, 20, 12, 22, 20, 20, 18, 18, 18, 18, 12, 12, 12, 12, 12, 12, 12, 22, 12, 12, 12, 22, 12, 22, 20, 20, 12, 12, 12, 22, 12, 22, 20, 20, 12, 22, 20, 20, 18, 18, 18, 18, 12, 12, 12, 22, 12, 22, 20, 20, 12, 22, 20, 20, 18, 18, 18, 18, 12, 22, 20, 20, 18, 18, 18, 18, 16, 16, 16, 16, 16, 16, 16, 16, 12, 12, 12, 12, 12, 12, 12, 22, 12, 12, 12, 22, 12, 22, 20, 20, 12, 12, 12, 22, 12, 22, 20, 20, 12, 22, 20, 20, 18, 18, 18, 18, 12, 12, 12, 22, 12, 22, 20, 20, 12, 22, 20, 20, 18, 18, 18, 18, 12, 22, 20, 20, 18, 18, 18, 18, 16, 16, 16, 16, 16, 16, 16, 16, 12, 12, 12, 22, 12, 22, 20, 20, 12, 22, 20, 20, 18, 18, 18, 18, 12, 22, 20, 20, 18, 18, 18, 18, 16, 16, 16, 16, 16, 16, 16, 16, 12, 22, 20, 20, 18, 18, 18, 18, 16, 16, 16, 16, 16, 16, 16, 16, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 12, 12, 12, 12, 12, 12, 12, 22, 12, 12, 12, 22, 12, 22, 20, 20, 12, 12, 12, 22, 12, 22, 20, 20, 12, 22, 20, 20, 18, 18, 18, 18, 12, 12, 12, 22, 12, 22, 20, 20, 12, 22, 20, 20, 18, 18, 18, 18, 12, 22, 20, 20, 18, 18, 18, 18, 16, 16, 16, 16, 16, 16, 16, 16, 12, 12, 12, 22, 12, 22, 20, 20, 12, 22, 20, 20, 18, 18, 18, 18, 12, 22, 20, 20, 18, 18, 18, 18, 16, 16, 16, 16, 16, 16, 16, 16, 12, 22, 20, 20, 18, 18, 18, 18, 16, 16, 16, 16, 16, 16, 16, 16, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 12, 12, 12, 22, 12, 22, 20, 20, 12, 22, 20, 20, 18, 18, 18, 18, 12, 22, 20, 20, 18, 18, 18, 18, 16, 16, 16, 16, 16, 16, 16, 16, 12, 22, 20, 20, 18, 18, 18, 18, 16, 16, 16, 16, 16, 16, 16, 16, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 12, 22, 20, 20, 18, 18, 18, 18, 16, 16, 16, 16, 16, 16, 16, 16, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 13];
b=[];for i=1:numel(stored)
a=dec2bin(i);
c=find(a=='1');
if numel(c)&gt;=(numel(a)+1)/2
if mod(numel(a)+1,2)==1
b=[b numel(a)+1];
else
d=c((numel(a)+1)/2);
b=[b 2*d];
end
else
b=[b numel(a)+1];
end
end
for i=1:numel(stored)
if (b(i))
if b(i)~=stored(i)
'error',
end
end
end

Since the algorithm verifies 2048 first testcases, I will blindly assume it would for any test case, so my algorithm works regarding few properties i discovered in this process without the pain of shifting and moving pointer:

1- if the twice the number of 1's in binary translation doesnt exceed the length of the sequnce L so the output isL+1 

2- if the sequence length is even and the previous condition isnt set so the output is same L+1

3- otherwise, the output is twice the L/2th index of 1.