A164493 Number of binary strings of length n with no substrings equal to 0010 0101 or 1001.

13, 22, 38, 65, 111, 190, 326, 559, 958, 1642, 2814, 4822, 8263, 14160, 24266, 41585, 71265, 122128, 209292, 358665, 614646, 1053322, 1805084, 3093384, 5301153, 9084622, 15568378, 26679633, 45721063, 78352486, 134273170, 230104815

Offset

4,1

Links

R. H. Hardin, Table of n, a(n) for n=4..500

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

Formula

G.f.: -x^4*(13-4*x+7*x^2-2*x^3+10*x^4+4*x^5+8*x^6) / ( -1+2*x-x^2+x^3-x^4+x^5+x^7 ). - R. J. Mathar, Jan 19 2011

Crossrefs

Sequence in context: A164456 A164410 A164421 * A164445 A164418 A301788

Adjacent sequences: A164490 A164491 A164492 * A164494 A164495 A164496

Keyword

nonn,easy

Author

R. H. Hardin, Aug 14 2009

Status

approved