cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A274501 a(n) = 25*binomial(n-1,6) + binomial(n-1,5).

Original entry on oeis.org

0, 1, 31, 196, 756, 2226, 5502, 12012, 23892, 44187, 77077, 128128, 204568, 315588, 472668, 689928, 984504, 1376949, 1891659, 2557324, 3407404, 4480630, 5821530, 7480980, 9516780, 11994255, 14986881, 18576936, 22856176, 27926536, 33900856, 40903632, 49071792
Offset: 5

Views

Author

Vincenzo Librandi, Jun 25 2016

Keywords

Crossrefs

Cf. A253945.

Programs

  • Magma
    [25*Binomial(n-1,6)+Binomial(n-1,5): n in [5..40]];
    
  • Maple
    A274501:=n->25*binomial(n-1,6) + binomial(n-1,5): seq(A274501(n), n=5..50); # Wesley Ivan Hurt, Jun 25 2016
  • Mathematica
    Table[25 Binomial[n - 1, 6] + Binomial[n - 1, 5], {n, 5, 40}]
    LinearRecurrence[{7,-21,35,-35,21,-7,1},{0,1,31,196,756,2226,5502},40] (* Harvey P. Dale, Mar 09 2022 *)
  • PARI
    concat(0, Vec(x^6*(1+24*x)/(1-x)^7 + O(x^99))) \\ Altug Alkan, Jun 27 2016

Formula

G.f.: x^6*(1 + 24*x)/(1-x)^7.
a(n) = 7*a(n-1) - 21*a(n-2) + 35*a(n-3) - 35*a(n-4) + 21*a(n-5) - 7*a(n-6) + a(n-7).
a(n) = (n-1)*(n-2)*(n-3)*(n-4)*(n-5)*(25*n-144)/720. - Wesley Ivan Hurt, Jun 25 2016