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A174634 a(n) = 3^n*F(n+2). 0
1, 6, 27, 135, 648, 3159, 15309, 74358, 360855, 1751787, 8503056, 41275251, 200353257, 972537030, 4720790403, 22915204479, 111232727064, 539935021503, 2620899608085, 12722114017782, 61754438526111, 299762341738371, 1455076971950112, 7063091991495675 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

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

Index entries for linear recurrences with constant coefficients, signature (3,9).

FORMULA

G.f.: (1+3x)/(1-3x-9x^2)=1/(-3x-1/(-3x-1)).

a(n) = (1/2+3*sqrt(5)/10)*(3/2+3*sqrt(5)/2)^n+(1/2-3*sqrt(5)/10)*(3/2-3*sqrt(5)/2)^n.

MATHEMATICA

Table[3^n Fibonacci[n+2], {n, 0, 30}] (* or *) LinearRecurrence[{3, 9}, {1, 6}, 30] (* Harvey P. Dale, May 23 2014 *)

CROSSREFS

Cf. A000045.

Sequence in context: A184279 A299598 A323928 * A018901 A215704 A137968

Adjacent sequences:  A174631 A174632 A174633 * A174635 A174636 A174637

KEYWORD

easy,nonn

AUTHOR

Paul Barry, Mar 24 2010

STATUS

approved

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Last modified August 9 05:12 EDT 2020. Contains 336319 sequences. (Running on oeis4.)