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A133523 Number of length n binary sequences with at most 2 of every adjacent 6 bits set. 6
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 (list; graph; refs; listen; history; text; internal format)
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: A005689 A212365 A131075 * A114805 A196722 A181120

Adjacent sequences:  A133520 A133521 A133522 * A133524 A133525 A133526

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 24 2007

STATUS

approved

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Last modified September 30 05:03 EDT 2020. Contains 337435 sequences. (Running on oeis4.)