A155658 a(n) = 11^n + 7^n - 1.

1, 17, 169, 1673, 17041, 177857, 1889209, 20310713, 220123681, 2398301297, 26219899849, 287288997353, 3152269663921, 34619601154337, 380428056656089, 4181995730925593, 45982962794141761, 505679659013280977

Offset: 0

Author

Mohammad K. Azarian, Jan 31 2009

Keywords

• nonn
• easy

Links

• G. C. Greubel, Table of n, a(n) for n = 0..958
• Index entries for linear recurrences with constant coefficients, signature (19,-95,77).

Crossrefs

Cf. A155638, A155639, A155640, A155641, A155642, A155643, A155644, A155645, A155646, A155647, A155648, A155649, A155650, A155651, A155652, A155653, A155654, A155655, A155656, A155657.

Programs

GAP

List([0..20], n -> 11^n+7^n-1); # G. C. Greubel, Nov 18 2018

Magma

[11^n+7^n-1: n in [0..20]]; // G. C. Greubel, Nov 18 2018

Mathematica

Table[11^n+7^n-1, {n,0,20}] (* G. C. Greubel, Nov 18 2018 *)

PARI

a(n)=11^n+7^n-1 \\ Charles R Greathouse IV, Jun 11 2015

Sage

[11^n+7^n-1 for n in range(20)] # G. C. Greubel, Nov 18 2018

Formula

G.f.: 1/(1-11*x) + 1/(1-7*x) - 1/(1-x).

E.g.f.: exp(11*x) + exp(7*x) - exp(x).

a(n) = 18*a(n-1)-77*a(n-2)-60 with a(0)=1, a(1)=17. - Vincenzo Librandi, Jul 21 2010