A121202 a(n) = 12*n + 7^n - 5^n.

0, 14, 48, 254, 1824, 13742, 102096, 745502, 5374272, 38400590, 272709744, 1928498750, 13597146720, 95668307438, 672119557392, 4717043931998, 33080342679168, 231867574534286, 1624598900645040, 11379821699045246

Offset: 0

Author

Mohammad K. Azarian, Aug 19 2006

Keywords

• nonn
• easy

Links

• Vincenzo Librandi, Table of n, a(n) for n = 0..1000
• Index entries for linear recurrences with constant coefficients, signature (14,-60,82,-35).

Crossrefs

Cf. A074616.

Programs

Magma

[7^n - 5^n + 12*n: n in [0..30]]; // Vincenzo Librandi, Feb 25 2013

Magma

I:=[0, 14, 48, 254]; [n le 4 select I[n] else 14*Self(n-1)-60*Self(n-2)+82*Self(n-3)-35*Self(n-4): n in [1..20]]; // Vincenzo Librandi, Feb 25 2013

Mathematica

CoefficientList[Series[2 (7 x - 74 x^2 + 211 x^3)/((1-x)^2 (1-5 x)(1-7 x)), {x, 0, 30}], x] (* Vincenzo Librandi, Feb 25 2013 *)

Formula

G.f.: 2*(7*x-74*x^2+211*x^3)/((1-x)^2*(1-5*x)*(1-7*x)). - Vincenzo Librandi, Feb 25 2013

a(n) = 14*a(n-1)-60*a(n-2)+82*a(n-3)-35*a(n-4). - Vincenzo Librandi, Feb 27 2013

Extensions

Edited by Ray Chandler, Sep 06 2006