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A164143
Number of binary strings of length n with equal numbers of 001 and 100 substrings
1
1, 2, 4, 6, 10, 20, 40, 80, 160, 320, 640, 1280, 2560, 5120, 10240, 20480, 40960, 81920, 163840, 327680, 655360, 1310720, 2621440, 5242880, 10485760, 20971520, 41943040, 83886080, 167772160, 335544320, 671088640, 1342177280, 2684354560, 5368709120
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=2; 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: A176716 A256056 A293281 * A095007 A005194 A171447
KEYWORD
nonn
AUTHOR
R. H. Hardin Aug 11 2009
STATUS
approved