A374409 Number of ways to write n as an ordered sum of a triangular number, a pentagonal number and a hexagonal number.

1, 3, 3, 2, 2, 2, 4, 5, 3, 2, 2, 4, 5, 3, 2, 4, 7, 4, 3, 3, 2, 7, 6, 5, 2, 2, 5, 4, 8, 6, 5, 3, 3, 6, 6, 4, 5, 7, 6, 5, 3, 6, 5, 8, 4, 3, 7, 5, 5, 4, 8, 11, 6, 4, 3, 5, 12, 7, 6, 1, 8, 7, 3, 6, 4, 6, 7, 12, 6, 5, 4, 9, 11, 11, 4, 1, 5, 8, 11, 7, 6, 9, 8, 4, 6, 7, 10, 3, 8, 4, 4, 10, 8, 9, 9, 11, 7, 7, 8, 10, 4

Offset: 0

Author

Seiichi Manyama, Jul 08 2024

Keywords

• nonn

Links

• Seiichi Manyama, Table of n, a(n) for n = 0..10000

Crossrefs

Cf. A000217, A000326, A000384, A240088.

Formula

G.f.: (Sum_{k>=0} x^(k*(k+1)/2)) * (Sum_{k>=0} x^(k*(3*k-1)/2)) * (Sum_{k>=0} x^(k*(2*k-1))).