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A130902 a(n) is the number of binary strings of length n such that there exist 4 or more ones in a subsequence of length 5 or less. 1
0, 0, 0, 1, 6, 16, 39, 91, 207, 463, 1014, 2188, 4671, 9888, 20786, 43435, 90302, 186934, 385547, 792642, 1625035, 3323393, 6782041, 13813588, 28087444, 57023945, 115614136, 234117510, 473564782, 956961354, 1932059363, 3897575310, 7856867785, 15827584881 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,5

LINKS

Matthew House, Table of n, a(n) for n = 0..3304

Index entries for linear recurrences with constant coefficients, signature (3,-1,-2,1,0,-4,-1,2,0,-1,2).

FORMULA

a(n) = 2^n - A125513(n).

G.f.: x^3*(-1-3*x+x^2+x^3-x^4+x^5+x^6) / ( (2*x-1)*(x^10+x^7-2*x^5-x^4-x^2-x+1) ). - R. J. Mathar, Nov 28 2011

CROSSREFS

Cf. A118647, A118646.

Sequence in context: A058272 A049712 A092274 * A009955 A160255 A213667

Adjacent sequences:  A130899 A130900 A130901 * A130903 A130904 A130905

KEYWORD

nonn

AUTHOR

Tanya Khovanova, Sep 28 2007

EXTENSIONS

More terms from Matthew House, Dec 26 2016

STATUS

approved

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Last modified March 26 23:19 EDT 2017. Contains 284141 sequences.