A074560 a(n) = 3^n + 8^n + 9^n.

3, 20, 154, 1268, 10738, 92060, 794314, 6882308, 59830498, 521657900, 4560585274, 39971171348, 351149544658, 3091623236540, 27274843749034, 241075518532388, 2134495208609218, 18928981642491980, 168109034193901594, 1494966906911109428, 13310586967150560178

Offset

0,1

Links

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

Index entries for linear recurrences with constant coefficients, signature (20,-123,216).

Formula

From Mohammad K. Azarian, Dec 30 2008: (Start)

G.f.: 1/(1-3*x) + 1/(1-8*x) + 1/(1-9*x).

E.g.f.: exp(3*x) + exp(8*x) + exp(9*x). (End)

a(n) = 20*a(n-1) - 123*a(n-2) + 216*a(n-3) for n>2. - Wesley Ivan Hurt, Aug 15 2016

Maple

A074560:=n->3^n + 8^n + 9^n: seq(A074560(n), n=0..25); # Wesley Ivan Hurt, Aug 15 2016

Mathematica

Table[3^n + 8^n + 9^n, {n, 0, 20}]
LinearRecurrence[{20, -123, 216}, {3, 20, 154}, 25] (* G. C. Greubel, Aug 15 2016 *)

Prog

(Magma) [3^n + 8^n + 9^n: n in [0..20]]; // Vincenzo Librandi, Aug 24 2011

Crossrefs

Cf. A001550, A001576, A001579, A034513, A074501-A074580.

Sequence in context: A091172 A091168 A126596 * A123355 A371815 A258791

Adjacent sequences: A074557 A074558 A074559 * A074561 A074562 A074563

Keyword

easy,nonn

Author

Robert G. Wilson v, Aug 23 2002

Status

approved