A074568 a(n) = 4^n + 7^n + 8^n.

3, 19, 129, 919, 6753, 50599, 383889, 2937079, 22607553, 174833479, 1357265649, 10571455639, 82577541153, 646711933159, 5076538019409, 39933007340599, 314712202247553, 2484447507541639, 19642880826869169, 155514358139135959

Offset

0,1

Links

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

Index entries for linear recurrences with constant coefficients, signature (19,-116,224).

Formula

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

G.f.: 1/(1-4*x) + 1/(1-7*x) + 1/(1-8*x).

E.g.f.: exp(4*x) + exp(7*x) + exp(8*x). (End)

a(n) = 19*a(n-1) - 116*a(n-2) + 224*a(n-3). - Wesley Ivan Hurt, Apr 19 2021

Mathematica

Table[4^n + 7^n + 8^n, {n, 0, 20}]
LinearRecurrence[{19, -116, 224}, {3, 19, 129}, 20] (* Harvey P. Dale, Aug 15 2016 *)

Prog

(Magma) [4^n + 7^n + 8^n: n in [0..20]]; // Vincenzo Librandi, Aug 14 2011
(PARI) vector(20, n, n--; 4^n + 7^n + 8^n) \\ G. C. Greubel, Nov 08 2018

Crossrefs

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

Sequence in context: A295371 A156069 A058860 * A219053 A074713 A199484

Adjacent sequences: A074565 A074566 A074567 * A074569 A074570 A074571

Keyword

easy,nonn

Author

Robert G. Wilson v, Aug 23 2002

Status

approved