A164441 Number of binary strings of length n with no substrings equal to 0000, 0110, or 1111.

1, 2, 4, 8, 13, 22, 36, 59, 97, 160, 263, 433, 712, 1172, 1928, 3173, 5220, 8590, 14133, 23256, 38264, 62962, 103596, 170461, 280475, 461501, 759354, 1249456, 2055862, 3382748, 5566002, 9158377, 15069284, 24795193, 40798275, 67129981, 110456415, 181746303

Offset

0,2

Links

Alois P. Heinz, Table of n, a(n) for n = 0..2000 (first 500 terms from R. H. Hardin)

Index entries for linear recurrences with constant coefficients, signature (0,1,1,2,1,1).

Formula

G.f.: -(x+1)*(x^2+1)*(x^5+x^4+2*x^3+x^2+x+1)/(x^6+x^5+2*x^4+x^3+x^2-1). - R. J. Mathar, Jan 19 2011

Crossrefs

Sequence in context: A330153 A244985 A164413 * A338761 A023600 A164437

Adjacent sequences: A164438 A164439 A164440 * A164442 A164443 A164444

Keyword

nonn,easy

Author

R. H. Hardin, Aug 14 2009

Extensions

Edited by Alois P. Heinz, Oct 27 2017

Status

approved