A100806 a(1) = 1; for n>=2, a(n) = A001221(n)-th positive integer not yet in the sequence.

1, 2, 3, 4, 5, 7, 6, 8, 9, 11, 10, 13, 12, 15, 16, 14, 17, 19, 18, 21, 22, 23, 20, 25, 24, 27, 26, 29, 28, 32, 30, 31, 34, 35, 36, 37, 33, 39, 40, 41, 38, 44, 42, 45, 46, 47, 43, 49, 48, 51, 52, 53, 50, 55, 56, 57, 58, 59, 54, 62, 60, 63, 64, 61, 66, 68, 65, 69, 70, 72, 67, 73