Number of steps to reach a single digit when map in A081502 is iterated.
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2
1 seqfan posts
Sat May 2 16:12:32 CEST 2009 [seqfan] Re: OEIS duplicate hunt