A120950 3^n+5^n-2n.

2, 6, 30, 146, 698, 3358, 16342, 80298, 397170, 1972790, 9824654, 49005250, 244672042, 1222297422, 6108298566, 30531927002, 152630937314, 763068593254, 3815084686078, 19074648589554, 95370918424986, 476847618556286

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

Magma

[3^n+5^n-2*n: n in [0..30]]; // Vincenzo Librandi, Feb 27 2013

Mathematica

Table[3^n + 5^n - 2 n, {n, 0, 30}] (* or *) CoefficientList[Series[2 (1 - 7 x + 17 x^2 - 19 x^3)/((1 - 5 x) (1 - 3 x) (1 - x)^2), {x, 0, 30}], x] (* Vincenzo Librandi, Feb 26 2013 *)
LinearRecurrence[{10,-32,38,-15},{2,6,30,146},30] (* Harvey P. Dale, Apr 27 2016 *)

Formula

G.f.: 2*(1-7*x+17*x^2-19*x^3)/((1-5*x)*(1-3*x)*(1-x)^2). - Vincenzo Librandi, Feb 26 2013

Extensions

Edited by Ray Chandler, Sep 06 2006