A121200 a(n) = 2*n + 7^n + 5^n.

2, 14, 78, 474, 3034, 19942, 133286, 901682, 6155442, 42306750, 292240894, 2026154890, 14085427850, 98109713558, 684326588502, 4778079088098, 33385518460258, 233393453440366, 1632228295176110, 11417968671701306

Offset: 0

Author

Mohammad K. Azarian, Aug 19 2006

Keywords

• nonn
• easy

Links

• Vincenzo Librandi, Table of n, a(n) for n = 0..1000

Crossrefs

Cf. A074616.

Programs

Magma

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

Mathematica

Table[2 n + 7^n + 5^n, {n, 0, 20}]  (* Harvey P. Dale, Mar 30 2011 *)
CoefficientList[Series[2 (1 - 7 x + x^2 + 29 x^3)/((1 - x)^2 (1 - 5 x)(1 - 7 x)), {x, 0, 30}], x] (* Vincenzo Librandi, Feb 25 2013 *)

Formula

G.f.: 2*(1-7*x+x^2+29*x^3)/((1-x)^2*(1-5*x)*(1-7*x)). - Vincenzo Librandi, Feb 25 2013

Extensions

Edited by Ray Chandler, Sep 06 2006