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A121401 a(n)=((sqrt(3)+1)^n+(sqrt(3)-1)^n)^2/2^(n+1). 1
2, 3, 8, 27, 98, 363, 1352, 5043, 18818, 70227, 262088, 978123, 3650402, 13623483, 50843528, 189750627, 708158978, 2642885283, 9863382152, 36810643323, 137379191138, 512706121227, 1913445293768, 7141075053843, 26650854921602 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

COMMENTS

a(n)=A001075(n)+1. Cf. A001075 a(n)=((2+sqrt(3))^n+(2-sqrt(3))^n)/2.

LINKS

Table of n, a(n) for n=0..24.

Index entries for linear recurrences with constant coefficients, signature (5,-5,1).

FORMULA

a(n)=A102206(n-1). O.g.f.: (1-3x)(x-2)/((x-1)(x^2-4x+1)). [From R. J. Mathar, Aug 07 2008]

MATHEMATICA

Table[((-1+Sqrt[3])^n+(1+Sqrt[3])^n)^2/(2^(n+1)), {n, 0, 25}]

LinearRecurrence[{5, -5, 1}, {2, 3, 8}, 25] (* Ray Chandler, Jan 27 2014 *)

CROSSREFS

Cf. A001075.

Sequence in context: A183948 A041503 A086613 * A318895 A093858 A080568

Adjacent sequences:  A121398 A121399 A121400 * A121402 A121403 A121404

KEYWORD

nonn

AUTHOR

Zak Seidov, Sep 06 2006

STATUS

approved

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Last modified October 27 23:26 EDT 2020. Contains 338047 sequences. (Running on oeis4.)