A164491 - OEIS

A164491

Number of binary strings of length n with no substrings equal to 0010 0100 or 1001.

13, 23, 40, 70, 122, 213, 371, 647, 1128, 1967, 3430, 5981, 10429, 18185, 31709, 55291, 96411, 168112, 293137, 511143, 891280, 1554125, 2709928, 4725302, 8239510, 14367235, 25052150, 43683438, 76170818, 132819068, 231596631, 403835084

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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 (1,1,0,0,1,1).

FORMULA

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

CROSSREFS

Sequence in context: A046119 A374102 A164416 * A164434 A164494 A164407

Adjacent sequences: A164488 A164489 A164490 * A164492 A164493 A164494

KEYWORD

nonn,easy

AUTHOR

R. H. Hardin, Aug 14 2009

STATUS

approved