A155642 9^n - 5^n + 1.

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

Offset

0,2

Links

Table of n, a(n) for n=0..18.

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.: e^(9*x)-e^(5*x)+e^x.

a(n)=14*a(n-1)-45*a(n-2)+32 with a(0)=1, a(1)=5 [From Vincenzo Librandi, Jul 21 2010]

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

Status

approved