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A091054 Expansion of (1-5x+2x^2)/((1-x)(1+2x)(1-6x)). 3
1, 0, 6, 18, 138, 762, 4698, 27930, 168090, 1007514, 6047130, 36278682, 217680282, 1306065306, 7836424602, 47018482074, 282111023514, 1692665878938, 10155995797914, 60935973738906, 365615844530586, 2193695062989210 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

Closed walks of length n at a vertex of the Johnson graph J(5,2). 6^n=A091054(n)+6*A091055(n)+3*4*A091056(n).

LINKS

Table of n, a(n) for n=0..21.

Index entries for linear recurrences with constant coefficients, signature (5,8,-12).

FORMULA

a(n)=6^n/10+(-2)^n/2+2/5

CROSSREFS

Sequence in context: A003496 A009582 A222913 * A012774 A306656 A027744

Adjacent sequences:  A091051 A091052 A091053 * A091055 A091056 A091057

KEYWORD

easy,nonn

AUTHOR

Paul Barry, Dec 17 2003

STATUS

approved

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Last modified July 21 02:02 EDT 2019. Contains 325189 sequences. (Running on oeis4.)