A074570 a(n) = 4^n + 8^n + 9^n.

3, 21, 161, 1305, 10913, 92841, 797681, 6896505, 59889473, 521900361, 4561574801, 39975188505, 351165790433, 3091688751081, 27275107401521, 241076577925305, 2134499460529793, 18928998693221001, 168109102525957841

Offset

0,1

Links

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

Index entries for linear recurrences with constant coefficients, signature (21,-140,288).

Formula

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

G.f.: 1/(1-4*x) + 1/(1-8*x) + 1/(1-9*x).

E.g.f.: exp(4*x) + exp(8*x) + exp(9*x). (End)

Mathematica

Table[4^n + 8^n + 9^n, {n, 0, 20}]

Prog

(Magma) [4^n + 8^n + 9^n: n in [0..20]]; // Vincenzo Librandi, Aug 14 2011
(PARI) vector(20, n, n--; 4^n + 8^n + 9^n) \\ G. C. Greubel, Nov 08 2018

Crossrefs

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

Sequence in context: A286918 A358953 A189508 * A136781 A225439 A180400

Adjacent sequences: A074567 A074568 A074569 * A074571 A074572 A074573

Keyword

easy,nonn

Author

Robert G. Wilson v, Aug 23 2002

Status

approved