A121213 7^n-5^n.

0, 2, 24, 218, 1776, 13682, 102024, 745418, 5374176, 38400482, 272709624, 1928498618, 13597146576, 95668307282, 672119557224, 4717043931818, 33080342678976, 231867574534082, 1624598900644824, 11379821699045018

Offset

0,2

Comments

a(n) = 2*A081200(n). - Reinhard Zumkeller, Aug 01 2010

Links

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

Index entries for linear recurrences with constant coefficients, signature (12,-35).

Formula

a(n)=12*a(n-1)-35*a(n-2) with a(0)=0, a(1)=2 - Vincenzo Librandi, Jul 21 2010

G.f.: 2*x/((5*x-1)*(7*x-1)). - Colin Barker, Nov 05 2012

Mathematica

Table[7^n-5^n, {n, 0, 20}] (* or *) LinearRecurrence[{12, -35}, {0, 2}, 20] (* Harvey P. Dale, Feb 10 2018 *)

Prog

(PARI) a(n)=7^n-5^n \\ Charles R Greathouse IV, Oct 07 2015

Crossrefs

Cf. A074616.

Sequence in context: A208533 A174668 A302444 * A147538 A180388 A288270

Adjacent sequences: A121210 A121211 A121212 * A121214 A121215 A121216

Keyword

nonn,easy

Author

Mohammad K. Azarian, Aug 19 2006

Status

approved