A023673 Convolution of A014306 with itself.
0, 0, 1, 2, 1, 2, 4, 4, 5, 6, 5, 6, 9, 8, 9, 10, 11, 12, 14, 14, 13, 14, 17, 16, 17, 18, 19, 20, 23, 22, 23, 24, 25, 26, 27, 26, 27, 30, 30, 30, 31, 32, 33, 36, 35, 36, 37, 38, 39, 40, 41, 42, 43, 46, 45, 46, 45, 46, 49, 48, 49, 50, 51, 52, 55, 54, 55, 56, 58, 58, 59
Offset: 1