A164448 Number of binary strings of length n with no substrings equal to 0001 0010 or 0111.

13, 21, 33, 51, 77, 116, 173, 257, 380, 561, 826, 1215, 1785, 2621, 3846, 5642, 8274, 12132, 17786, 26073, 38218, 56018, 82105, 120338, 176371, 258492, 378846, 555234, 813743, 1192607, 1747859, 2561621, 3754247, 5502126, 8063767, 11818035

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 (2,0,-1,0,-1,1).

Formula

G.f.: -x^4*(13-5*x-9*x^2-2*x^3-4*x^4+8*x^5) / ( (1+x)*(x^3+x-1)*(x-1)^2 ). - R. J. Mathar, Jan 19 2011

Mathematica

LinearRecurrence[{2, 0, -1, 0, -1, 1}, {13, 21, 33, 51, 77, 116}, 40] (* Harvey P. Dale, Apr 10 2019 *)

Crossrefs

Sequence in context: A164438 A164490 A164460 * A164424 A164450 A164461

Adjacent sequences: A164445 A164446 A164447 * A164449 A164450 A164451

Keyword

nonn,easy

Author

R. H. Hardin, Aug 14 2009

Status

approved