A128051 (n^3+n)*7^n.

14, 490, 10290, 163268, 2184910, 26118078, 288240050, 2997696520, 29780961966, 285300001490, 2653572489106, 24083839729740, 214124712999470, 1870539234917542, 16094233518706770, 136653810502199312

Offset: 1

Author

Mohammad K. Azarian, May 02 2007

Keywords

• nonn
• easy

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A128796, A128960, A128985, A129002.

Programs

Magma

[(n^3 + n)*7^n: n in [1..20]]; // Vincenzo Librandi, Feb 22 2013

Mathematica

Table[(n^3 + n) * 7^n, {n, 30}] (* or *) CoefficientList[Series[14 (1 + 7 x + 49 x^2)/(1 - 7 x)^4, {x, 0, 20}], x] (* Vincenzo Librandi, Feb 22 2013 *)

Formula

G.f.: 14*x*(1 + 7*x + 49*x^2)/(1 - 7*x)^4. - Vincenzo Librandi, Feb 22 2013