In prime factorization of n replace each prime by its reversal (in decimal notation).
1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 31, 14, 15, 16, 71, 18, 91, 20, 21, 22, 32, 24, 25, 62
1 seqfan posts
Tue Jun 23 19:48:20 CEST 2009 [seqfan] A151764 -- circular definition?