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.

A205550 Symmetric matrix by antidiagonals: C(max(g(i),g(j)),min(g(i),g(j))), where g(k)=2k-1.

Original entry on oeis.org

1, 3, 3, 5, 1, 5, 7, 10, 10, 7, 9, 35, 1, 35, 9, 11, 84, 21, 21, 84, 11, 13, 165, 126, 1, 126, 165, 13, 15, 286, 462, 36, 36, 462, 286, 15, 17, 455, 1287, 330, 1, 330, 1287, 455, 17, 19, 680, 3003, 1716, 55, 55, 1716, 3003, 680, 19, 21, 969, 6188, 6435, 715
Offset: 1

Views

Author

Clark Kimberling, Jan 28 2012

Keywords

Examples

			Northwest corner:
1....3....5....7....9....11
3....1....10...35...84...165
5....10...1....21...126..462
7....35...21...1....36...330
		

Crossrefs

Cf. A205456.

Programs

  • Mathematica
    g[k_] := 2 k - 1;
    f[i_, j_] := Binomial[Max[g[i], g[j]], Min[g[i], g[j]]]
    TableForm[Table[f[i, j], {i, 1, 10}, {j, 1, 10}]]
    Flatten[Table[f[i, n + 1 - i], {n, 1, 14}, {i, 1, n}]]