A320592 Number of partitions of n with four parts in which no part occurs more than twice.

1, 1, 3, 4, 6, 8, 12, 14, 19, 23, 29, 34, 42, 48, 58, 66, 77, 87, 101, 112, 128, 142, 160, 176, 197, 215, 239, 260, 286, 310, 340, 366, 399, 429, 465, 498, 538, 574, 618, 658, 705, 749, 801, 848, 904, 956, 1016, 1072, 1137, 1197, 1267, 1332, 1406, 1476, 1556

Offset: 6

Author

Alois P. Heinz, Oct 16 2018

Keywords

• nonn
• easy

Links

• Alois P. Heinz, Table of n, a(n) for n = 6..10000

Crossrefs

Column k=4 of A209318.

Formula

G.f.: -(x^4-x^2-1)*x^6/((x^2+1)*(x^2+x+1)*(x+1)^2*(x-1)^4).