A374382 Number of ways to write n as an ordered sum of a triangular number, a square and an odd square.
0, 1, 2, 1, 1, 2, 1, 1, 2, 1, 3, 4, 2, 3, 1, 2, 4, 2, 2, 3, 4, 1, 1, 3, 2, 4, 5, 3, 4, 4, 3, 4, 4, 2, 3, 5, 2, 5, 5, 2, 5, 5, 1, 1, 4, 3, 7, 5, 1, 4, 6, 5, 2, 7, 5, 6, 6, 2, 4, 4, 5, 5, 7, 2, 5, 9, 3, 2, 7, 1, 5, 9, 1, 6, 5, 5, 4, 4, 3, 7, 7, 5, 5, 5, 5, 5, 10, 2, 7, 7, 4, 8, 7, 5, 4, 10, 6, 4, 3, 2, 9
Offset: 0
Keywords
Examples
2 = A000217(1) + A000290(0) + A016754(0) = A000217(0) + A000290(1) + A016754(0). So a(2) = 2.
Links
- Seiichi Manyama, Table of n, a(n) for n = 0..10000
Formula
G.f.: (Sum_{k>=0} x^(k*(k+1)/2)) * (Sum_{k>=0} x^(k^2)) * (Sum_{k>=0} x^((2*k+1)^2)).