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.

Showing 1-2 of 2 results.

A203763 Vandermonde sequence using x^2 - xy + y^2 applied to (1,1,2,2,...,[n/2]).

Original entry on oeis.org

1, 1, 9, 324, 777924, 16810159716, 69136555917409344, 4549499535875623543259136, 115306876482136485813839025883201536, 73061199694724861313901918528002630365482598400
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 + 1)/2]; z = 16;
    u := Product[f[j]^2 - f[j] f[k] + f[k]^2, {j, 1, k - 1}]
    v[n_] := Product[u, {k, 2, n}]
    Table[v[n], {n, 1, z}]        (* A203763 *)
    Table[v[n + 1]/v[n], {n, 1, z}]  (* A203764 *)
    Table[Sqrt[v[n + 1]/v[n]], {n, 1, 20}]  (* A203765 *)

A203764 v(n+1)/v(n), where v=A203763.

Original entry on oeis.org

1, 9, 36, 2401, 21609, 4112784, 65804544, 25344958401, 633623960025, 413815190632704, 14897346862777344, 14823103693846716801, 726332080998489123249, 1025131531800200888254464, 65608418035212856848285696
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 + 1)/2]; z = 16;
    u := Product[f[j]^2 - f[j] f[k] + f[k]^2, {j, 1, k - 1}]
    v[n_] := Product[u, {k, 2, n}]
    Table[v[n], {n, 1, z}]          (* A203763 *)
    Table[v[n + 1]/v[n], {n, 1, z}] (* A203764 *)
    Table[Sqrt[v[n + 1]/v[n]], {n, 1, 20}]  (* A203765 *)
Showing 1-2 of 2 results.