A077127 a(0) = 1, a(1) = 2, a(n) = smallest number other than n, non-coprime to n and not occurring earlier.

1, 2, 4, 6, 8, 10, 3, 14, 12, 15, 5, 22, 9, 26, 7, 18, 20, 34, 16, 38, 24, 27, 11, 46, 21, 30, 13, 33, 32, 58, 25, 62, 28, 36, 17, 40, 39, 74, 19, 42, 35, 82, 44, 86, 48, 50, 23, 94, 45, 56, 52, 54, 60, 106, 51, 65, 49, 63, 29, 118, 55, 122, 31, 57, 66, 70, 64, 134, 72, 75, 68