A164484 Number of binary strings of length n with no substrings equal to 0001 0111 or 1100.

13, 20, 31, 48, 74, 114, 175, 268, 410, 626, 955, 1456, 2218, 3378, 5143, 7828, 11914, 18130, 27587, 41976, 63866, 97170, 147839, 224924, 342202, 520626, 792075, 1205056, 1833354, 2789234, 4243495, 6455972, 9821994, 14942994, 22733971

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 (2,0,0,-3,2).

Formula

G.f.: -x^4*(13-6*x-9*x^2-14*x^3+17*x^4) / ( (2*x^3+x^2-1)*(x-1)^2 ). - R. J. Mathar, Jan 19 2011

Crossrefs

Sequence in context: A164464 A164467 A164505 * A164502 A164474 A164478

Adjacent sequences: A164481 A164482 A164483 * A164485 A164486 A164487

Keyword

nonn,easy

Author

R. H. Hardin, Aug 14 2009

Status

approved