A164434 Number of binary strings of length n with no substrings equal to 0000 0101 or 1010.

13, 23, 40, 70, 122, 213, 372, 650, 1135, 1982, 3462, 6047, 10561, 18445, 32216, 56268, 98275, 171643, 299787, 523599, 914499, 1597232, 2789674, 4872353, 8509886, 14863080, 25959362, 45339756, 79188896, 138308673, 241565308, 421909890

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

Formula

G.f.: -x^4*(-13-10*x-17*x^2-4*x^3+7*x^4+12*x^5+8*x^6) ) / ( 1-x-2*x^3-x^4+x^6+x^7 ). - R. J. Mathar, Jan 19 2011

a(n) = a(n-1)+2*a(n-3)+a(n-4)-a(n-6)-a(n-7). - Wesley Ivan Hurt, May 20 2021

Crossrefs

Sequence in context: A046119 A164416 A164491 * A164494 A164407 A259216

Adjacent sequences: A164431 A164432 A164433 * A164435 A164436 A164437

Keyword

nonn

Author

R. H. Hardin Aug 14 2009

Status

approved