Numbers having at least two distinct or a total of three prime factors.
6, 8, 10, 12, 14, 15, 16, 18, 20, 21, 22, 24, 26, 27, 28, 30, 32, 33, 34, 35, 36, 38, 39
2 seqfan posts
Mon Jan 26 00:54:36 CET 2009 [seqfan] Re: Add n to the composite a(n): the result is a composite too