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.

A239958 Number of partitions p of n such that (number of distinct parts of p) >= max(p) - min(p).

Original entry on oeis.org

1, 1, 2, 3, 5, 6, 9, 11, 16, 18, 25, 30, 39, 47, 59, 69, 89, 105, 126, 153, 184, 215, 259, 307, 362, 426, 501, 583, 687, 800, 923, 1080, 1252, 1439, 1666, 1917, 2202, 2533, 2900, 3311, 3792, 4326, 4915, 5605, 6366, 7205, 8180, 9259, 10458, 11815, 13322
Offset: 0

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Author

Clark Kimberling, Mar 30 2014

Keywords

Examples

			a(6) counts all of the 15 partitions of 7 except these 4:  61, 52, 511, 1111111.
		

Crossrefs

Programs

  • Mathematica
    z = 60; d[p_] := d[p] = Length[DeleteDuplicates[p]]; f[p_] := f[p] = Max[p] - Min[p]; g[n_] := g[n] = IntegerPartitions[n];
    Table[Count[g[n], p_ /; d[p] < f[p]], {n, 0, z}]  (*A239954*)
    Table[Count[g[n], p_ /; d[p] <= f[p]], {n, 0, z}] (*A239955*)
    Table[Count[g[n], p_ /; d[p] == f[p]], {n, 0, z}] (*A239956*)
    Table[Count[g[n], p_ /; d[p] > f[p]], {n, 0, z}]  (*A034296*)
    Table[Count[g[n], p_ /; d[p] >= f[p]], {n, 0, z}] (*A239958*)
    ndpQ[p_]:=Module[{prt=Union[p]},Length[prt]>=(Max[prt]-Min[prt])]; Table[Length[Select[ IntegerPartitions[ n],ndpQ]],{n,0,50}] (* Harvey P. Dale, Dec 31 2023 *)

Formula

a(n) + A239954(n) = A000041(n) for n >= 0.