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.

A202945 v(n+1)/v(n), where v=A203773.

Original entry on oeis.org

1, 2, 100, 800, 152100, 2737800, 1156000000, 36992000000, 27619018944400, 1380950947220000, 1606635342973440000, 115677744694087680000, 193495923191341225000000, 18962600472751440050000000
Offset: 1

Views

Author

Clark Kimberling, Jan 05 2012

Keywords

Comments

See A093883 for a discussion and guide to related sequences.

Programs

  • Mathematica
    f[j_] := Floor[j/2]; z = 20;
    u := Product[f[j]^2 + f[k]^2, {j, 1, k - 1}]
    v[n_] := Product[u, {k, 2, n}]
    Table[v[n], {n, 1, z}]         (* A203773 *)
    Table[v[n + 1]/v[n], {n, 1, z}]  (* A202945 *)
    Table[Sqrt[v[n + 1]/v[n]], {n, 1, z}]
    Table[Sqrt[v[2 n]/v[2 n - 1]], {n, 1, z}]  (* A203774 *)
    Table[Sqrt[v[2 n + 1]/(2 v[2 n])],
       {n, 1, z}]  (* A203775 *)
    %/%%          (* A000027 *)