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A164161
Number of binary strings of length n with equal numbers of 0001 and 1000 substrings.
5
1, 2, 4, 8, 14, 26, 50, 100, 200, 400, 800, 1600, 3200, 6400, 12800, 25600, 51200, 102400, 204800, 409600, 819200, 1638400, 3276800, 6553600, 13107200, 26214400, 52428800, 104857600, 209715200, 419430400, 838860800, 1677721600, 3355443200
OFFSET
0,2
LINKS
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. [From N. J. A. Sloane, Apr 07 2012]
PROG
(Empirical) (bc) (z is number of 0's) z=3; for(i=0; i<=500; i++) { if(i<=z)a=2^i else if(i<=2*z)a=2*a-2 else a=2*a; a }
CROSSREFS
Sequence in context: A164167 A164169 A164166 * A068011 A048238 A048140
KEYWORD
nonn
AUTHOR
R. H. Hardin, Aug 11 2009
STATUS
approved