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A118004 a(n) = 9^n - 4^n. 5
0, 5, 65, 665, 6305, 58025, 527345, 4766585, 42981185, 387158345, 3485735825, 31376865305, 282412759265, 2541798719465, 22876524019505, 205890058352825, 1853015893884545, 16677164519797385, 150094566577522385 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..18.

Eric Weisstein's World of Mathematics, Cantor Square Fractal

Index entries for linear recurrences with constant coefficients, signature (13,-36)

FORMULA

a(n) =5*A016153(n).

a(n) = 13*a(n-1) - 36*a(n-2), n>=2. - Vincenzo Librandi, Mar 16 2011

G.f.: 5*x / ( (9*x-1)*(4*x-1) ). - R. J. Mathar, Mar 18 2011

MATHEMATICA

Table[9^n-4^n, {n, 0, 20}] (* or *) LinearRecurrence[{13, -36}, {0, 5}, 20] (* Harvey P. Dale, May 11 2017 *)

PROG

(PARI) a(n)=9^n-4^n \\ Charles R Greathouse IV, Oct 07 2015

CROSSREFS

Cf. A016153.

Sequence in context: A195579 A296369 A061184 * A281232 A236321 A199024

Adjacent sequences:  A118001 A118002 A118003 * A118005 A118006 A118007

KEYWORD

nonn,easy

AUTHOR

Eric W. Weisstein, Apr 09 2006

STATUS

approved

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Last modified July 31 17:51 EDT 2021. Contains 346376 sequences. (Running on oeis4.)