A155636 a(n) = 9^n + 5^n - 1.

1, 13, 105, 853, 7185, 62173, 547065, 4861093, 43437345, 389373613, 3496550025, 31429887733, 282673677105, 2543086531453, 22882895970585, 205921649672773, 1853172776742465, 16677944639119693, 150098449994264745, 1350870791159320213, 12157760826488569425, 109419465968670562333

Offset: 0

Author

Mohammad K. Azarian, Jan 30 2009

Keywords

• nonn
• easy

Links

• Paolo Xausa, Table of n, a(n) for n = 0..1000
• Index entries for linear recurrences with constant coefficients, signature (15,-59,45).

Crossrefs

Cf. A155624, A155625, A155626, A155627, A155628, A155629, A155630, A155631, A155632, A155633, A155634, A155635.

Programs

Mathematica

Table[9^n + 5^n - 1, {n, 0, 25}] (* Paolo Xausa, Aug 03 2024 *)

PARI

a(n)=9^n+5^n-1 \\ Charles R Greathouse IV, Jun 11 2015

Formula

G.f.: 1/(1-9*x)+1/(1-5*x)-1/(1-x).

E.g.f.: exp(9*x)+exp(5*x)-exp(x).

a(n) = 14*a(n-1)-45*a(n-2)-32 with a(0) = 1, a(1) = 13. - Vincenzo Librandi, Jul 21 2010