The Lucas-nacci Numbers
Jelly, 12 bytes

;2U+¥Ð¡-,1ZḢ


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Background

We can extend F and L to -1 by defining F(-1) = 1 and L(-1) = -1. This is consistent with the recursive function.

Our program starts with

-1  1
 0  2


In each step, to form the next pair, we reverse the last pair and add it to the penultimate pair. For example:

[0, 2] U+¥ [-1, 1] -&gt; [2, 0] + [-1, 1] -&gt; [1, 1]


If we continue this process for a few more steps, we get

-1  1
 0  2
 1  1
 1  3
 4  2
 3  7
11  5


The Lucas-nacci sequence is simply the left column.

How it works

;2U+¥Ð¡-,1ZḢ  Niladic link. No implicit input.
              Since the link doesn't start with a nilad, the argument 0 is used.

;2            Concatenate the argument with 2, yielding [0, 2].
       -,1    Yield [-1, 1]. This is [L(-1), F(-1)].
    ¥         Create a dyadic chain of the two atoms to the left:
  U             Reverse the left argument.
   +            Add the reversed left argument and the right one, element-wise.
     Ð¡       For reasons‡, read a number n from STDIN.
              Repeatedly call the dyadic link U+¥, updating the right argument with
              the value of the left one, and the left one with the return value.
              Collect all intermediate results.
          Z   Zip the list of results, grouping the first and seconds coordinates.
           Ḣ  Head; select the list of first coordinates.


‡ Ð¡ peeks at the two links to the left: 2 and U+¥. Since the leftmost one is a nilad, it cannot be the body of the loop. Therefore, U+¥ is used as body and a number is read from input. Since there are no command-line arguments, that number is read from STDIN.