a(n) = p-1 if n=p, p if n=p^e and e<>1, 1 otherwise; p a prime.
1, 1, 2, 2, 4, 1, 6, 2, 3, 1, 10, 1, 12, 1, 1, 2, 16, 1, 18, 1, 1, 1, 22, 1, 5, 1, 3, 1, 28, 1, 30
1 seqfan posts
Thu Dec 17 01:51:39 CET 2009 [seqfan] Re: Divisibility sequences in OEIS.