A155646 a(n) = 8^n + 6^n - 1.

1, 13, 99, 727, 5391, 40543, 308799, 2377087, 18456831, 144295423, 1134207999, 8952731647, 70896259071, 562816507903, 4476410675199, 35654557073407, 284296086618111, 2268726473129983, 18115958466150399, 144724547815866367

Offset

0,2

Links

Table of n, a(n) for n=0..19.

Index entries for linear recurrences with constant coefficients, signature (15,-62,48).

Formula

G.f.: 1/(1-8*x)+1/(1-6*x)-1/(1-x). E.g.f.: e^(8*x)+e^(6*x)-e^x.

a(n) = 14*a(n-1)-48*a(n-2)-35 with a(0)=1, a(1)=13. [Vincenzo Librandi, Jul 21 2010]

a(0)=1, a(1)=13, a(2)=99, a(n) = 15*a(n-1)-62*a(n-2)+48*a(n-3). [Harvey P. Dale, Jul 17 2011]

Mathematica

Table[8^n+6^n-1, {n, 0, 20}] (* or *) LinearRecurrence[{15, -62, 48}, {1, 13, 99}, 20] (* Harvey P. Dale, Jul 17 2011 *)

Prog

(PARI) a(n)= 8^n+6^n-1 \\ Charles R Greathouse IV, Jul 31 2011

Crossrefs

Cf. A155628, A155629, A155630, A155631, A155632, A155633, A155634, A155635, A155636, A155637, A155638, A155639, A155640, A155641, A155642, A155643, A155644, A155645.

Sequence in context: A295271 A034270 A201427 * A089936 A196928 A266002

Adjacent sequences: A155643 A155644 A155645 * A155647 A155648 A155649

Keyword

nonn,easy

Author

Mohammad K. Azarian, Jan 31 2009

Status

approved