A155652 a(n) = 9^n - 6^n + 1.

1, 4, 46, 514, 5266, 51274, 484786, 4503034, 41367106, 377342794, 3426318226, 31018262554, 280252754146, 2528805134314, 22798428290866, 205420947110074, 1850199078944386, 16660255040221834, 149993075340330706, 1350242357932981594, 12154009300616865826, 109397052180871981354

Offset

0,2

Links

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

Index entries for linear recurrences with constant coefficients, signature (16,-69,54).

Formula

G.f.: 1/(1-9*x)-1/(1-6*x)+1/(1-x).

E.g.f.: exp(9*x)-exp(6*x)+exp(x).

a(n)=15*a(n-1)-54*a(n-2)+40 with a(0)=1, a(1)=4. - Vincenzo Librandi, Jul 21 2010

Mathematica

A155652[n_] := 9^n - 6^n + 1; Array[A155652, 25, 0] (* Paolo Xausa, Apr 05 2026 *)

Prog

(PARI) a(n)=9^n-6^n+1^n \\ Charles R Greathouse IV, Jun 11 2015

Crossrefs

Cf. A155628, A155629, A155630, A155631, A155632, A155633, A155634, A155635, A155636, A155637, A155638, A155639, A155640, A155641, A155642, A155643, A155644, A155645, A155646, A155647, A155648, A155649, A155650, A155651.

Sequence in context: A320229 A097952 A097643 * A222098 A197131 A235132

Adjacent sequences: A155649 A155650 A155651 * A155653 A155654 A155655

Keyword

nonn,easy

Author

Mohammad K. Azarian, Jan 31 2009

Extensions

More terms from Paolo Xausa, Apr 05 2026

Status

approved