A074569 a(n) = 4^n + 7^n + 9^n.

3, 20, 146, 1136, 9218, 76880, 653186, 5622896, 48877058, 428036240, 3770308226, 33362580656, 296287600898, 2638821947600, 23555283963266, 210639767346416, 1886257414388738, 16909829393522960, 151723117614386306

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,-127,252).

Formula

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

G.f.: 1/(1-4*x) + 1/(1-7*x) + 1/(1-9*x).

E.g.f.: exp(4*x) + exp(7*x) + exp(9*x). (End)

Mathematica

Table[4^n + 7^n + 9^n, {n, 0, 20}]

Prog

(Magma) [4^n + 7^n + 9^n: n in [0..20]]; // Vincenzo Librandi, Aug 14 2011
(PARI) vector(20, n, n--; 4^n + 7^n + 9^n) \\ G. C. Greubel, Nov 08 2018

Crossrefs

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

Sequence in context: A009156 A074573 A068571 * A026303 A154627 A320350

Adjacent sequences: A074566 A074567 A074568 * A074570 A074571 A074572

Keyword

easy,nonn

Author

Robert G. Wilson v, Aug 23 2002

Status

approved