A083590 Expansion of 1/((1-5*x)*(1-x^5)).

1, 5, 25, 125, 625, 3126, 15630, 78150, 390750, 1953750, 9768751, 48843755, 244218775, 1221093875, 6105469375, 30527346876, 152636734380, 763183671900, 3815918359500, 19079591797500, 95397958987501, 476989794937505

Offset: 0

Author

Paul Barry, May 02 2003

Keywords

• easy
• nonn

Links

• Vincenzo Librandi, Table of n, a(n) for n = 0..1000
• Index entries for linear recurrences with constant coefficients, signature (5,0,0,0,1,-5).

Crossrefs

Cf. A083589, A033139, A000975.

Programs

Magma

[Floor(625*(5^(n+1)+1)/3124): n in [0..40]]; // G. C. Greubel, Oct 10 2017

Mathematica

CoefficientList[Series[1/((1-5x)(1-x^5)),{x,0,40}],x] (* Vincenzo Librandi, Apr 04 2012 *)
LinearRecurrence[{5,0,0,0,1,-5},{1,5,25,125,625,3126},30] (* Harvey P. Dale, Jan 21 2023 *)

PARI

Vec(1/(1-5*x)/(1-x^5)+O(x^99)) \\ Charles R Greathouse IV, Apr 04 2012

Formula

a(n) = floor(625*(5^(n+1)+1)/3124). - Tani Akinari, Jul 09 2013