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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.

A241408 a(n) is the number of partitions of n such that the number of parts having multiplicity > 1 is a part.

Original entry on oeis.org

0, 0, 1, 1, 2, 4, 5, 9, 11, 18, 24, 34, 46, 63, 83, 109, 147, 189, 245, 315, 406, 513, 650, 817, 1030, 1287, 1593, 1978, 2450, 3013, 3689, 4523, 5511, 6711, 8140, 9852, 11892, 14334, 17217, 20657, 24727, 29531, 35197, 41894, 49761, 59000, 69861, 82542, 97393
Offset: 0

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Author

Clark Kimberling, Apr 22 2014

Keywords

Examples

			a(6) counts these 5 partitions: 411, 3111, 2211, 21111, 111111; e.g., the number of parts of 2211 that have multiplicity > 1 is 2, which counts 1 (with multiplicity 2) and 2 (also with multiplicity 2), so that 2211 is a term because 2 is a part.
		

Crossrefs

Programs

  • Mathematica
    z = 30; f[n_] := f[n] = IntegerPartitions[n]; e[p_] := Length[DeleteDuplicates[Select[p, Count[p, #] > 1 &]]]; d[p_] := Length[DeleteDuplicates[p]];
    Table[Count[f[n], p_ /; MemberQ[p, e[p]]], {n, 0, z}]  (* A241408 *)
    Table[Count[f[n], p_ /; MemberQ[p, e[p]] && MemberQ[p, d[p]]], {n, 0, z}]  (* A241409 *)
    Table[Count[f[n], p_ /; ! MemberQ[p, e[p]] && MemberQ[p, d[p]] ], {n, 0, z}] (* A241410 *)
    Table[Count[f[n], p_ /; MemberQ[p, e[p]] && ! MemberQ[p, d[p]] ], {n, 0, z}] (* A241411  *)
    Table[Count[f[n], p_ /; ! MemberQ[p, e[p]] && ! MemberQ[p, d[p]] ], {n, 0, z}] (* A241412  *)