A158422 a[n] = number of bit strings of length n which have exactly as many substrings 000 as substrings 111.

1, 2, 4, 6, 10, 16, 28, 46, 82, 142, 256, 460, 846, 1556, 2912, 5454, 10332, 19618, 37506, 71894, 138432, 267136, 517142, 1002904, 1949366, 3794686, 7399060, 14444992, 28236426, 55251992, 108224818, 212167258, 416284478, 817369732

Offset

0,2

References

This was motivated by problem 11424 in the 2009 March issue of the American Mathematical monthly.

Links

R. H. Hardin, Table of n, a(n) for n=0..500

Shalosh B. Ekhad and Doron Zeilberger, Automatic Solution of Richard Stanley's Amer. Math. Monthly Problem #11610 and ANY Problem of That Type, arXiv preprint arXiv:1112.6207, 2011. See subpages for rigorous derivations of g.f., recurrence, asymptotics for this sequence.

Crossrefs

Sequence in context: A052185 A136241 A160444 * A018161 A288599 A067880

Adjacent sequences: A158419 A158420 A158421 * A158423 A158424 A158425

Keyword

nonn

Author

Dan Jurca (dan.jurca(AT)csueastbay.edu), Mar 18 2009

Extensions

a(11)-a(500)from R. H. Hardin, Aug 10 2009

Status

approved