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A164474 Number of binary strings of length n with no substrings equal to 0001 0101 or 1100 1
13, 20, 31, 48, 74, 115, 179, 278, 433, 675, 1051, 1638, 2554, 3980, 6204, 9673, 15078, 23505, 36646, 57128, 89059, 138845, 216454, 337443, 526073, 820135, 1278566, 1993268, 3107464, 4844460, 7552429, 11774088, 18355543, 28615940, 44611686 (list; graph; refs; listen; history; text; internal format)
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 (2,-1,2,-3,1).

FORMULA

G.f. -x^4*(13-6*x+4*x^2-20*x^3+8*x^4) / ( (x-1)*(x^4-2*x^3-x+1) ). - R. J. Mathar, Jan 19 2011

MATHEMATICA

LinearRecurrence[{2, -1, 2, -3, 1}, {13, 20, 31, 48, 74}, 40] (* Harvey P. Dale, Dec 28 2017 *)

CROSSREFS

Sequence in context: A164505 A164484 A164502 * A164478 A164463 A164470

Adjacent sequences:  A164471 A164472 A164473 * A164475 A164476 A164477

KEYWORD

nonn

AUTHOR

R. H. Hardin Aug 14 2009

STATUS

approved

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Last modified September 26 06:16 EDT 2021. Contains 347664 sequences. (Running on oeis4.)