A120245 a(1) = 1. a((m(m+1)/2 +k) = a(m) + a(k), 1 <= k <= m+1, m >= 1.

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