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.

A241640 Number of partitions p of n such that (number of even numbers in p) > (number of odd numbers in p).

Original entry on oeis.org

0, 0, 1, 0, 2, 0, 3, 1, 6, 4, 10, 11, 20, 23, 32, 44, 57, 77, 90, 129, 150, 208, 236, 334, 381, 522, 595, 803, 936, 1234, 1435, 1861, 2193, 2770, 3291, 4105, 4884, 6001, 7172, 8678, 10418, 12487, 14969, 17791, 21330, 25164, 30181, 35398, 42337, 49463, 59057
Offset: 0

Views

Author

Clark Kimberling, Apr 27 2014

Keywords

Comments

Each number in p is counted once, regardless of its multiplicity.

Examples

			a(6) counts these 3 partitions:  6, 42, 222.
		

Crossrefs

Programs

  • Mathematica
    z = 30; f[n_] := f[n] = IntegerPartitions[n]; s0[p_] := Count[Mod[DeleteDuplicates[p], 2],   0];
    s1[p_] := Count[Mod[DeleteDuplicates[p], 2], 1];
    Table[Count[f[n], p_ /; s0[p] < s1[p]], {n, 0, z}]  (* A241636 *)
    Table[Count[f[n], p_ /; s0[p] <= s1[p]], {n, 0, z}] (* A241637 *)
    Table[Count[f[n], p_ /; s0[p] == s1[p]], {n, 0, z}] (* A241638 *)
    Table[Count[f[n], p_ /; s0[p] >= s1[p]], {n, 0, z}] (* A241639 *)
    Table[Count[f[n], p_ /; s0[p] > s1[p]], {n, 0, z}]  (* A241640 *)

Formula

a(n) = A241639(n) - A241638(n) for n >= 0.
a(n) + A241636(n) + A241638(n) = A000041(n) for n >= 0.
a(n) = Sum_{k<0} A242618(n,k). - Alois P. Heinz, May 19 2014