A120978 2n+5^n-3^n.

0, 4, 20, 104, 552, 2892, 14908, 75952, 384080, 1933460, 9706596, 48651000, 243609208, 1219108828, 6098732684, 30503229248, 152544843936, 762810312996, 3814309845172, 19072324066696, 95363944856264, 476826697849964

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 (10, -32, 38, -15).

Crossrefs

Cf. A074606, A005058.

Programs

Mathematica

Table[2 n + 5^n - 3^n, {n, 0, 30}] (* or *) LinearRecurrence[{10, -32, 38, -15},{0, 4, 20, 104}, 30] (* Harvey P. Dale, Jun 15 2011 *)
CoefficientList[Series[2 x (2 - 10 x + 16 x^2)/((1 - x)^2(1 - 5 x)(1 - 3 x)), {x, 0, 30}], x] (* Vincenzo Librandi, Feb 23 2013 *)

Formula

a(0)=0, a(1)=4, a(2)=20, a(3)=104, a(n) = 10*a(n-1)-32*a(n-2)+38*a(n-3)-15*a(n-4) [Harvey P. Dale, Jun 15 2011]

G.f.: 2*x*(2-10*x+16*x^2)/((1-x)^2*(1-5*x)*(1-3*x)). - Vincenzo Librandi, Feb 23 2013

Extensions

Edited by Ray Chandler, Sep 06 2006