A133523 Number of length n binary sequences with at most 2 of every adjacent 6 bits set.

1, 2, 4, 7, 11, 16, 22, 34, 54, 86, 136, 212, 324, 498, 772, 1202, 1873, 2915, 4524, 7012, 10873, 16877, 26213, 40716, 63227, 98154, 152353, 236493, 367150, 570034, 885032, 1374048, 2133185, 3311680, 5141292, 7981842, 12391897, 19238551, 29867908

Offset

0,2

Links

R. H. Hardin, Table of n, a(n) for n = 0..215

Formula

Empirical: a(n) = a(n-1) + a(n-3) + 2*a(n-6) - 2*a(n-9) - a(n-10) - a(n-12) + a(n-15). - R. H. Hardin, Apr 29 2012.

Empirical g.f.: (1 + x + 2*x^2 + 2*x^3 + 2*x^4 + x^5 - 3*x^6 - 3*x^7 - 4*x^8 - 2*x^9 - x^10 + x^12 + x^13 + x^14) / ((1 - x)*(1 + x + x^2)*(1 - x - x^4 - 2*x^6 - x^7 + x^12)). - Colin Barker, Feb 22 2018

Crossrefs

Sequence in context: A212365 A131075 A365698 * A114805 A196722 A181120

Adjacent sequences: A133520 A133521 A133522 * A133524 A133525 A133526

Keyword

nonn

Author

R. H. Hardin, Dec 24 2007

Status

approved