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.

A128023 a(n) = A128022(n)/n.

Original entry on oeis.org

1, 1, 1, 2, 3, 5, 9, 16, 28, 51, 92, 169, 312, 580, 1082, 2029, 3819, 7214, 13669, 25971, 49468, 94439, 180666, 346277, 664852, 1278561, 2462414, 4748941, 9170369, 17729380, 34314929, 66485175, 128940946, 250297130, 486291567, 945566936
Offset: 1

Views

Author

Leroy Quet, Feb 11 2007

Keywords

Crossrefs

Cf. A128022.

Programs

  • Mathematica
    f[l_List] := Block[{n = Length[l] + 1},Append[l, Ceiling[Sum[k*l[[k]], {k, n - 1}]/n]]];Nest[f, {1}, 36] (* Ray Chandler, Feb 12 2007 *)

Formula

a(1)=1, a(n) = ceiling(Sum_{k=1..n-1} A128022(k)/n).

Extensions

Extended by Ray Chandler, Feb 12 2007

A128020 a(n) = the multiple of n which is > (sum{k=1 to n-1} a(k)) and is <= (n + sum{k=1 to n-1} a(k)).

Original entry on oeis.org

1, 2, 6, 12, 25, 48, 98, 200, 396, 790, 1584, 3168, 6331, 12670, 25335, 50672, 101354, 202698, 405403, 810800, 1621599, 3243196, 6486391, 12972792, 25945575, 51891164, 103782330, 207564644, 415129287, 830258580, 1660517170, 3321034336
Offset: 1

Views

Author

Leroy Quet, Feb 11 2007

Keywords

Crossrefs

Programs

  • Mathematica
    f[l_List] := Block[{n = Length[l] + 1},Append[l, n*(1 + Floor[Plus @@ l/n])]];Nest[f, {}, 33] (* Ray Chandler, Feb 12 2007 *)

Formula

a(n) = n * (1+ floor(sum{k=1 to n-1} a(k) /n)).

Extensions

Extended by Ray Chandler, Feb 12 2007

A129571 A129360 * A007318.

Original entry on oeis.org

1, 1, 1, 0, 2, 1, 1, 3, 3, 1, 0, 4, 6, 4, 1, 0, 4, 10, 10, 5, 1, 0, 6, 15, 20, 15, 6, 1, 1, 7, 21, 35, 35, 21, 7, 1, 0, 6, 27, 56, 70, 56, 28, 8, 1, 0, 8, 36, 84, 126, 126, 84, 36, 9, 1
Offset: 1

Views

Author

Gary W. Adamson, Apr 22 2007

Keywords

Comments

First 10 row sums match A128022: (1, 2, 3, 8, 15, 30, 63, 128, 252, 510, ...). A129570 = A007318 * A129360.

Examples

			First few rows of the triangle:
  1;
  1,  1;
  0,  2,  1;
  1,  3,  3,  1;
  0,  4,  6,  4,  1;
  0,  4, 10, 10,  5,  1;
  0,  6, 15, 20, 15,  6,  1;
  1,  7, 21, 35, 35, 21,  7,  1;
  ...
		

Crossrefs

Formula

A129360 * A007318 as infinite lower triangular matrices.
Showing 1-3 of 3 results.