ASCII Triangle Ripple Ok, my first golf question. Please be gentle :) I know there's way too many ascii puzzles :P but here we go.
The task is simple, use your favorite programming language to print a triangle ripple. The input should be the size of the ripple.
Each triangle is evenly spaced out. Basically, you keep adding the triangles until there is not enough space for the smallest triangle.
You are allowed white spaces anywhere you want as long as the ripples are the same as the example with the correct size.
Example
q)g 1
__
\/
q)g 2
____
\  /
 \/
q)g 3
______
\    /
 \  /
  \/
q)g 4
________
\  __  /
 \ \/ /
  \  /
   \/
q)g 5
__________
\  ____  /
 \ \  / /
  \ \/ /
   \  /
    \/
q)g 6
____________
\  ______  /
 \ \    / /
  \ \  / /
   \ \/ /
    \  /
     \/
q)g 7
______________
\  ________  /
 \ \  __  / /
  \ \ \/ / /
   \ \  / /
    \ \/ /
     \  /
      \/
q)g 8
________________
\  __________  /
 \ \  ____  / /
  \ \ \  / / /
   \ \ \/ / /
    \ \  / /
     \ \/ /
      \  /
       \/

As usual, shortest code wins :)
GNU sed -nr, 210
A start:
s/1/__/g
p
s#_(.*)_#\\\1/#
s#\\__#\\  #
s#__/#  /#
ta
:a
p
s#(.*) _{6}(_*) # \1\\  \2  /#;ta
s#(.*)  (  )# \1\2#;
s#(.*) _(_*)_ # \1\\\2/#
y/_/ /
Tc
:b
p
:c
s#(.*)((\\)  ( *)(/)|()()()\\/)# \1\3\4\5#;tb

Input is a positive unary integer via STDIN, as per this meta-question.
Output:
$ for i in 1 11 111 1111 11111 111111 1111111; do sed -rnf triripple.sed &lt;&lt;&lt; $i; done
__
\/
 
____
\  /
 \/
  
______
\    /
 \  /
  \/
   
________
\  __  /
 \ \/ /
  \  /
   \/
    
__________
\  ____  /
 \ \  / /
  \ \/ /
   \  /
    \/
     
____________
\  ______  /
 \ \    / /
  \ \  / /
   \ \/ /
    \  /
     \/
      
______________
\  ________  /
 \ \  __  / /
  \ \ \/ / /
   \ \  / /
    \ \/ /
     \  /
      \/
       
$