A108228 a(n) = (A003961(n) - 1)/2, a permutation of the nonnegative integers.
0, 1, 2, 4, 3, 7, 5, 13, 12, 10, 6, 22, 8, 16, 17, 40, 9, 37, 11, 31, 27, 19, 14, 67, 24, 25, 62, 49, 15, 52, 18, 121, 32, 28, 38, 112, 20, 34, 42, 94, 21, 82, 23, 58, 87, 43, 26, 202, 60, 73, 47, 76, 29, 187, 45, 148, 57, 46, 30, 157, 33, 55, 137, 364, 59, 97, 35, 85, 72
Offset: 1