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A164480 Number of binary strings of length n with no substrings equal to 0001, 0110 or 1100. 1
1, 2, 4, 8, 13, 21, 34, 55, 88, 142, 229, 370, 598, 967, 1564, 2530, 4093, 6622, 10714, 17335, 28048, 45382, 73429, 118810, 192238, 311047, 503284, 814330, 1317613, 2131942, 3449554, 5581495, 9031048, 14612542, 23643589, 38256130, 61899718, 100155847 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Alois P. Heinz, Table of n, a(n) for n = 0..2000 (first 500 terms from R. H. Hardin)

Index entries for linear recurrences with constant coefficients, signature (2, 0, -1).

FORMULA

From Colin Barker, Oct 27 2017: (Start)

G.f.: -(x^8+x^5+x^4-x^3-1)/((x-1)*(x^2+x-1)).

a(n) = 2*a(n-1) - a(n-3) for n>6.

(End)

PROG

(PARI) Vec(-(x^8+x^5+x^4-x^3-1)/((x-1)*(x^2+x-1)) + O(x^60)) \\ Colin Barker, Oct 27 2017

CROSSREFS

Sequence in context: A164420 A164457 A164419 * A134035 A078157 A144119

Adjacent sequences:  A164477 A164478 A164479 * A164481 A164482 A164483

KEYWORD

nonn,easy

AUTHOR

R. H. Hardin, Aug 14 2009

EXTENSIONS

Edited by Alois P. Heinz, Oct 27 2017

STATUS

approved

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Last modified November 15 15:59 EST 2018. Contains 317239 sequences. (Running on oeis4.)