A025944 - OEIS

A025944

Expansion of 1/((1-2x)(1-3x)(1-7x)(1-9x)).

1, 21, 292, 3414, 36439, 368607, 3604114, 34449888, 324158197, 3016246233, 27838148416, 255387389322, 2332396465075, 21228942680499, 192722119904398, 1746130572580116, 15796595736313873, 142739306095633005

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OFFSET

0,2

LINKS

Table of n, a(n) for n=0..17.

Index entries for linear recurrences with constant coefficients, signature (21,-149,411,-378)

FORMULA

G.f.: 1/((1-2*x)*(1-3*x)*(1-7*x)*(1-9*x)).

a(n) = 3^(n+2)/8 -2^(n+3)/35 -7^(n+3)/40 +3^(2*n+5)/28. - R. J. Mathar, Jun 04 2013

a(n) = 21*a(n-1) - 149*a(n-2) + 411*a(n-3) - 378*a(n-4). - Wesley Ivan Hurt, Oct 29 2022

CROSSREFS

Sequence in context: A101700 A275359 A022291 * A025962 A181381 A081137

Adjacent sequences: A025941 A025942 A025943 * A025945 A025946 A025947

KEYWORD

nonn

AUTHOR

N. J. A. Sloane.

STATUS

approved