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A176812 Expansion of 3*(1+x)/(1-2*x-5*x^2). 1
3, 9, 33, 111, 387, 1329, 4593, 15831, 54627, 188409, 649953, 2241951, 7733667, 26677089, 92022513, 317430471, 1094973507, 3777099369, 13029066273, 44943629391, 155032590147, 534783327249, 1844729605233, 6363375846711 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

COMMENTS

Binomial transform of A026532 after dropping A026532(0). [From R. J. Mathar, Apr 27 2010]

LINKS

Table of n, a(n) for n=0..23.

Index entries for linear recurrences with constant coefficients, signature (2,5).

FORMULA

Binet form: a(n)=2^n*(((3 + Sqrt[6])/2)*((1 + Sqrt[6])/2)^n + ((3 - Sqrt[6])/2)*((1 - Sqrt[6])/2)^n) = 3*A180168(n).

MATHEMATICA

a[n_] = 2^n*(((3 + Sqrt[ 6])/2)*((1 + Sqrt[6])/2)^n + ((3 - Sqrt[6])/2)*((1 - Sqrt[6])/2)^n); Table[FullSimplify[a[n]], {n, 0, 30}]

CoefficientList[Series[(-3(1+x))/(5x^2+2x-1), {x, 0, 40}], x]  (* Harvey P. Dale, Feb 24 2011 *)

CROSSREFS

Sequence in context: A343735 A037129 A148987 * A192430 A323790 A148988

Adjacent sequences:  A176809 A176810 A176811 * A176813 A176814 A176815

KEYWORD

nonn,easy

AUTHOR

Roger L. Bagula, Apr 26 2010

STATUS

approved

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Last modified December 1 16:44 EST 2021. Contains 349430 sequences. (Running on oeis4.)