Mallow's Sequence

An Integer Sequence given by the recurrence relation

$$a(n)=a(a(n-2))+a(n-a(n-2))$$

with $a(1)=a(2)=1$. The first few values are 1, 1, 2, 3, 3, 4, 5, 6, 6, 7, 7, 8, 9, 10, 10, 11, 12, 12, 13, 14, ... (Sloane's A005229).

See also Hofstadter-Conway $10,000 Sequence, Hofstadter's Q-Sequence

References

Mallows, C. ``Conway's Challenging Sequence.'' Amer. Math. Monthly 98, 5-20, 1991.

Sloane, N. J. A. Sequence A005229/M0441 in ``An On-Line Version of the Encyclopedia of Integer Sequences.'' http://www.research.att.com/~njas/sequences/eisonline.html and Sloane, N. J. A. and Plouffe, S. The Encyclopedia of Integer Sequences. San Diego: Academic Press, 1995.