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.

A308916 Irregular triangular array: row n shows positions of strict partitions of n among all partitions of n, using Mathematica ordering.

Original entry on oeis.org

1, 1, 1, 2, 1, 2, 1, 2, 3, 1, 2, 3, 6, 1, 2, 3, 5, 6, 1, 2, 3, 5, 6, 9, 1, 2, 3, 5, 6, 8, 9, 14, 1, 2, 3, 5, 6, 8, 9, 14, 15, 23, 1, 2, 3, 5, 6, 8, 9, 13, 14, 15, 21, 24, 1, 2, 3, 5, 6, 8, 9, 13, 14, 15, 21, 22, 25, 33, 34, 1, 2, 3, 5, 6, 8, 9, 13, 14, 15
Offset: 1

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Author

Clark Kimberling, Jun 30 2019

Keywords

Examples

			1
1
1   2
1   2
1   2   3
1   2   3   6
1   2   3   5   6
1   2   3   5   6   9
1   2   3   5   6   8   9   14
1   2   3   5   6   8   9   14   15   23
Strict partitions of 6: {6}, {5, 1}, {4, 2}, {3, 2, 1}, which occupy positions 1,2,3,6 in the ordering of all partitions of 6: {6}, {5, 1}, {4, 2}, {4, 1, 1}, {3, 3}, {3, 2, 1}, {3, 1, 1, 1}, {2, 2, 2}, {2, 2, 1, 1}, {2, 1, 1, 1, 1}, {1, 1, 1, 1, 1, 1}
		

Crossrefs

Programs

  • Mathematica
    p[n_] := IntegerPartitions[n];
    d[n_] := Select[p[n], Max[Length /@ Split@#] == 1 &];
    t = Table[Flatten[Table[Position[p[n], d[n][[k]]], {k, 1, Length[d[n]]}]], {n, 1, 15}]
    Flatten[t]  (* A308916, sequence *)