A155642 a(n) = 9^n - 5^n + 1.

1, 5, 57, 605, 5937, 55925, 515817, 4704845, 42656097, 385467365, 3477018777, 31332231485, 282185395857, 2540645125205, 22870688939337, 205860614516525, 1852867600961217, 16676418760213445, 150090820599733497, 1350832644186663965, 12157570091625288177, 109418512294354156085

Offset

0,2

Links

Paolo Xausa, Table of n, a(n) for n = 0..1000

Index entries for linear recurrences with constant coefficients, signature (15,-59,45).

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)=5. - Vincenzo Librandi, Jul 21 2010

Mathematica

A155642[n_] := 9^n - 5^n + 1; Array[A155642, 25, 0] (* Paolo Xausa, Mar 08 2026 *)

Prog

(PARI) a(n)=9^n-5^n+1 \\ Charles R Greathouse IV, Dec 22 2011

Crossrefs

Sequence in context: A107339 A139260 A114466 * A322248 A277831 A333091

Adjacent sequences: A155639 A155640 A155641 * A155643 A155644 A155645

Keyword

nonn,easy

Author

Mohammad K. Azarian, Jan 30 2009

Extensions

More terms from Paolo Xausa, Mar 08 2026

Status

approved