A374406 Number of ways to write n as an ordered sum of a triangular number, a square and a hexagonal number.

1, 3, 3, 2, 3, 3, 3, 5, 3, 2, 6, 5, 3, 3, 1, 5, 9, 5, 3, 5, 5, 4, 7, 3, 2, 9, 5, 4, 5, 6, 6, 8, 8, 2, 6, 4, 5, 11, 8, 3, 6, 5, 4, 9, 4, 7, 11, 8, 2, 5, 8, 7, 13, 5, 6, 10, 7, 6, 4, 7, 8, 9, 4, 2, 11, 12, 5, 12, 6, 3, 15, 10, 6, 9, 7, 4, 12, 6, 5, 8, 9, 10, 14, 7, 4, 15, 4, 9, 7, 4, 5, 12, 15, 7, 10, 10, 7, 13, 10, 3

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, A000290, A000384, A160324, A240088.

Formula

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