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 1-3 of 3 results.

A274193 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-1,3k) for n > 0, k > 1.

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, 2, 1, 1, 1, 1, 2, 2, 2, 1, 1, 1, 1, 3, 3, 2, 2, 1, 1, 1, 1, 3, 4, 3, 2, 2, 1, 1, 1, 1, 4, 4, 4, 3, 2, 2, 1, 1, 1, 1, 5, 6, 5, 4, 3, 2, 2, 1, 1, 1, 1, 6, 7, 7, 5, 4, 3, 2, 2, 1, 1, 1, 1, 8, 9, 8, 7, 5, 4, 3
Offset: 0

Views

Author

Clark Kimberling, Jun 14 2016

Keywords

Examples

			First  10 rows:
1
1   1
1   1   1
1   1   1   1
1   2   1   1   1
1   2   2   1   1   1
1   2   2   2   1   1   1
1   3   3   2   2   1   1   1
1   3   4   3   2   2   1   1   1
1   4   4   4   3   2   2   1   1   1
		

Crossrefs

Cf. A274194 (row sums), A274195, A274200 (limiting reverse row), A274190, A274196.

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, 3 k]];
    t = Table[g[n, k], {n, 0, 14}, {k, 0, n}]
    TableForm[t] (* A274193 array *)
    u = Flatten[t] (* A274193 sequence *)

A274195 Decimal expansion of limiting ratio described in Comments.

Original entry on oeis.org

1, 2, 9, 8, 6, 4, 0, 6, 4, 0, 8, 6, 1, 7, 0, 4, 6, 4, 5, 6, 9, 3, 3, 4, 4, 1, 6, 1, 5, 8, 5, 2, 8, 1, 2, 2, 0, 4, 8, 5, 5, 3, 9, 7, 7, 9, 8, 6, 5, 3, 7, 4, 5, 6, 3, 3, 1, 4, 5, 5, 4, 9, 3, 9, 2, 7, 3, 5, 7, 5, 5, 6, 3, 1, 8, 8, 7, 7, 3, 1, 4, 3, 1, 1, 2, 8
Offset: 1

Views

Author

Clark Kimberling, Jun 16 2016

Keywords

Comments

As in A274193, define g(n,k) = 1 for n >= 0; g(n,k) = 0 if k > n; g(n,k) = g(n-1,k-1) + g(n-1,3k) for n > 0, k > 1. The sum of numbers in the n-th row of the array {g(n,k)} is given by A274194, and "limiting ratio" = limit of A274194(n)/A274194(n-1).

Examples

			Limiting ratio = 1.2986406408617046456933441615...
		

Crossrefs

Cf. A274193, A274194, A274198, A274210 (reciprocal).

Programs

  • Mathematica
    z = 1500; 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, 3 k]];
    t = Table[g[n, k], {n, 0, z}, {k, 0, n}];
    w = Map[Total, t];   (* A274194 *)
    u = N[w[[z]]/w[[z - 1]], 100]
    RealDigits[u][[1]] (* A274195 *)

A274210 Decimal expansion of the reciprocal of the constant in A274195.

Original entry on oeis.org

7, 7, 0, 0, 3, 5, 9, 6, 5, 7, 1, 2, 9, 2, 9, 1, 9, 8, 7, 9, 2, 2, 1, 4, 1, 6, 6, 1, 9, 6, 7, 9, 8, 9, 9, 3, 7, 0, 3, 2, 9, 4, 1, 7, 2, 3, 4, 0, 9, 3, 7, 2, 9, 6, 4, 2, 9, 4, 7, 0, 5, 2, 2, 0, 0, 8, 0, 8, 6, 3, 5, 9, 3, 8, 2, 6, 4, 6, 7, 0, 9, 4, 0, 8, 9, 0
Offset: 0

Views

Author

Clark Kimberling, Jun 16 2016

Keywords

Examples

			Limiting ratio = 0.770035965712929198792214166196...
		

Crossrefs

Programs

  • Mathematica
    z = 1600; 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, 3 k]];
    t = Table[g[n, k], {n, 0, z}, {k, 0, n}];
    w = Map[Total, t]; (*A274194*)
    u = N[w[[z]]/w[[z + 1]], 100]
    RealDigits[u][[1]] (*A274210*)
Showing 1-3 of 3 results.