Multiplicative persistence: number of iterations of "multiply digits" needed to reach a number < 10.
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 1, 1, 1, 1
2 seqfan posts
Wed Apr 1 21:05:52 CEST 2009 [seqfan] Re: Base sequences like A067581, suggestion: Go Factorial!