A112975 Lexicographically smallest permutation of the natural numbers such that each term has a common divisor with at least two earlier terms, a(n)=n for n<4.

1, 2, 3, 6, 4, 8, 9, 10, 12, 14, 15, 5, 16, 18, 20, 21, 7, 22, 24, 25, 26, 27, 28, 30, 32, 33, 11, 34, 35, 36, 38, 39, 13, 40, 42, 44, 45, 46, 48, 49, 50, 51, 17, 52, 54, 55, 56, 57, 19, 58, 60, 62, 63, 64, 65, 66, 68, 69, 23, 70, 72, 74, 75, 76, 77, 78, 80, 81, 82, 84, 85, 86