The sequence 1, 1, 2, 2, 3, 4, 4, 4, 5, 6, 7, 7, ... (Sloane's A004001) defined by the recurrence ,
References
Bloom, D. M. ``Newman-Conway Sequence.'' Solution to Problem 1459. Math. Mag. 68, 400-401, 1995.
Sloane, N. J. A. Sequence
A004001/M0276
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.