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 1-5 of 5 results.

A274197 Row sums of the array A274196, defined by 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, 2, 3, 4, 5, 7, 9, 11, 13, 17, 21, 25, 30, 38, 46, 55, 67, 83, 100, 121, 148, 180, 217, 264, 321, 388, 470, 572, 693, 838, 1018, 1237, 1497, 1814, 2205, 2675, 3239, 3930, 4773, 5785, 7010, 8510, 10326, 12514, 15177, 18422, 22340, 27084, 32862, 39872, 483458
Offset: 0

Views

Author

Clark Kimberling, Jun 16 2016

Keywords

Comments

See A274198 for the limit of a(n)/a(n-1).

Examples

			(g(7,k)) = (1,2,2,2,1,1,1,1), so that a(7) = 11.
		

Crossrefs

Programs

  • Mathematica
    z = 150; 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, z}, {k, 0, n}]; w = Map[Total, t];

A274201 Limiting reverse row of the array A274196.

Original entry on oeis.org

1, 1, 1, 1, 2, 2, 2, 3, 4, 4, 5, 7, 8, 9, 12, 15, 17, 21, 27, 32, 37, 47, 58, 68, 82, 103, 124, 147, 181, 223, 266, 321, 396, 480, 575, 701, 858, 1033, 1248, 1525, 1852, 2232, 2712, 3305, 3998, 4836, 5886, 7148, 8644, 10487, 12752, 15453, 18713, 22731, 27596
Offset: 1

Views

Author

Clark Kimberling, Jun 16 2016

Keywords

Comments

The triangular array (g(n,k)) in A274196 is defined as follows: g(n,k) = 1 for n >= 0; g(n,k) = 0 if k > n; g(n,k) = g(n-1,k-1) + g(n-1,4) for n > 0, k > 1.

Crossrefs

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]];
    z = 300; w = Reverse[Table[g[z, k], {k, 0, z}]];
    Take[w, z/3]

A274190 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-1,2k) for n > 0, k > 1.

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 2, 2, 1, 1, 1, 3, 3, 2, 1, 1, 1, 4, 4, 3, 2, 1, 1, 1, 5, 6, 5, 3, 2, 1, 1, 1, 7, 8, 7, 5, 3, 2, 1, 1, 1, 9, 12, 10, 8, 5, 3, 2, 1, 1, 1, 13, 17, 15, 11, 8, 5, 3, 2, 1, 1, 1, 18, 24, 22, 17, 12, 8, 5, 3, 2, 1, 1, 1, 25, 35, 32
Offset: 0

Views

Author

Clark Kimberling, Jun 13 2016

Keywords

Examples

			First  10 rows:
1
1   1
1   1   1
1   2   1   1
1   2   2   1   1
1   3   3   2   1   1
1   4   4   3   2   1   1
1   5   6   5   3   2   1   1
1   7   8   7   5   3   2   1   1
1   9   12  10  8   5   3   2   1
		

Crossrefs

Cf. A274184 (row sums), A274192, A274199 (limiting reverse row), A274193, 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, 2 k]];
    t = Table[g[n, k], {n, 0, 14}, {k, 0, n}]
    TableForm[t] (* A274190 array *)
    u = Flatten[t] (* A274190 sequence *)

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 *)

A274198 Decimal expansion of limiting ratio described in Comments.

Original entry on oeis.org

1, 2, 1, 2, 9, 7, 9, 9, 2, 7, 0, 4, 9, 3, 6, 7, 7, 1, 8, 9, 1, 5, 2, 6, 4, 0, 2, 5, 5, 5, 1, 1, 2, 8, 7, 8, 2, 2, 9, 0, 2, 7, 9, 5, 6, 9, 9, 8, 9, 8, 8, 9, 8, 2, 0, 7, 0, 0, 8, 7, 4, 0, 8, 0, 6, 8, 2, 8, 0, 2, 4, 2, 2, 2, 4, 4, 4, 3, 7, 3, 5, 3, 1, 3, 4, 9
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-1,4k) for n > 0, k > 1. The sum of numbers in the n-th row of the array {g(n,k)} is given by A274197, and "limiting ratio" = limit of A274197(n)/A274197(n-1).

Examples

			limiting ratio = 1.21297992704936771891526402555...
		

Crossrefs

Cf. A274196, A274197, A274192, A274193, A274211 (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, 4 k]];
    t = Table[g[n, k], {n, 0, z}, {k, 0, n}];
    w = Map[Total, t];   (* A274197 *)
    u = N[w[[z]]/w[[z - 1]], 100]
    RealDigits[u][[1]] (* A274198 *)
Showing 1-5 of 5 results.