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.

A274196 Triangular array read by rows: g(n,k) = 1 for n >= 0; g(n,k) = 0 if k > n; g(n,k) = g(n-1,k-1) + g(n-1,4k) for n > 0, k > 1.

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 2, 2, 1, 1, 1, 1, 1, 2, 2, 2, 1, 1, 1, 1, 1, 2, 2, 2, 2, 1, 1, 1, 1, 1, 3, 3, 2, 2, 2, 1, 1, 1, 1, 1, 3, 4, 3, 2, 2, 2, 1, 1, 1, 1, 1, 3, 4, 4, 3, 2, 2, 2, 1, 1, 1, 1, 1, 4, 4, 4, 4, 3, 2, 2
Offset: 0

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Author

Clark Kimberling, Jun 16 2016

Keywords

Examples

			First  10 rows:
1
1   1
1   1   1
1   1   1   1
1   1   1   1   1
1   2   1   1   1   1
1   2   2   1   1   1   1
1   2   2   2   1   1   1   1
1   2   2   2   2   1   1   1   1
1   3   3   2   2   2   1   1   1   1
		

Crossrefs

Cf. A274197 (row sums), A274201 (limiting reverse row), A274190.

Programs

  • Mathematica
    g[n_, 0] = g[n, 0] = 1;
    g[n_, k_] := g[n, k] = If[k > n, 0, g[n - 1, k - 1] + g[n - 1, 4 k]];
    t = Table[g[n, k], {n, 0, 14}, {k, 0, n}]
    TableForm[t] (* A274196 array *)
    u = Flatten[t] (* A274196 sequence *)