Smallest number <>n, not occurring earlier and having as many distinct prime factors as n has, with a(1) = 1.
1, 3, 2, 5, 4, 10, 8, 7, 11, 6, 9, 14, 16, 12, 18, 13, 19, 15, 17, 21, 20, 24, 25, 22, 23, 28
2 seqfan posts
Wed Apr 8 00:55:37 CEST 2009 [seqfan] Re: Symmetric Relations and Self-Inverse Permutations