A004057 - OEIS

A004057

Expansion of (1-x)/( (1+x)*(1-2*x)*(1-3*x)*(1-4*x)).

1, 7, 39, 191, 875, 3843, 16423, 68887, 285219, 1170059, 4768127, 19336863, 78141883, 314953555, 1266977751, 5089412519, 20422176467, 81882328731, 328110270895, 1314184126255, 5261965982571, 21063553061987

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OFFSET

0,2

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 0..1000

Index entries for linear recurrences with constant coefficients, signature (8,-17,-2,24).

FORMULA

a(n) = (1/30)*(20*2^n - 135*3^n + 144*4^n + (-1)^n).

MATHEMATICA

CoefficientList[Series[(1-x)/((1+x)(1-2x)(1-3x)(1-4x)), {x, 0, 30}], x] (* or *) LinearRecurrence[{8, -17, -2, 24}, {1, 7, 39, 191}, 30] (* Harvey P. Dale, Oct 22 2019 *)

PROG

(Magma) [(1/30)* (20*2^n - 135*3^n + 144*4^n + (-1)^n): n in [0..30]]; // Vincenzo Librandi, Oct 08 2011

CROSSREFS

First differences of A099110.

Sequence in context: A128554 A225617 A032207 * A081898 A034267 A198767

Adjacent sequences: A004054 A004055 A004056 * A004058 A004059 A004060

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane

STATUS

approved