A129007 (n^3+n^2)*7^n.

14, 588, 12348, 192080, 2521050, 29647548, 322828856, 3320525376, 32686421670, 310722773900, 2871078430836, 25910889640272, 229239398622962, 1993975834176060, 17091221435794800, 144629713838903552

Offset: 1

Author

Mohammad K. Azarian, May 01 2007

Keywords

• nonn
• easy

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..1000
• Index entries for linear recurrences with constant coefficients, signature (28,-294,1372,-2401).

Crossrefs

Cf. A128796, A036289.

Programs

Magma

[(n^3+n^2)*7^n: n in [1..25]]; // Vincenzo Librandi, Feb 12 2013

Mathematica

Table[(n^3+n^2)7^n,{n,30}] (* or *) LinearRecurrence[{28,-294,1372,-2401},{14,588,12348,192080},30] (* Harvey P. Dale, Nov 21 2012 *)
CoefficientList[Series[14 (1 + 14 x)/(1 - 7 x)^4, {x, 0, 30}], x] (* Vincenzo Librandi, Feb 12 2013 *)

Formula

a(1)=14, a(2)=588, a(3)=12348, a(4)=192080, a(n)=28*a(n-1)-294*a(n-2)+ 1372*a(n-3)-2401*a(n-4). - Harvey P. Dale, Nov 21 2012

G.f.: 14*x*(1+14*x)/(1-7*x)^4. - Vincenzo Librandi, Feb 12 2013