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%I #12 Jan 13 2020 09:33:19
%S 0,4,3,3,3,3,3,2,3,1,1,4,3,3,3,3,3,2,3,1,4,3,3,2,2,2,2,3,2,1,3,3,3,2,
%T 2,2,2,3,2,1,3,2,2,3,2,3,3,3,2,1,3,2,2,2,2,2,3,2,3,1,3,2,2,3,2,2,2,2,
%U 2,1,3,2,2,3,3,2,2,2,2,1,2,3,3,3,2,2,2,2,2,1,3,2,2,2,3,2,2,2,3
%N 7-multiplicative persistence: number of iterations of "multiply 7th powers of digits" needed to reach 0 or 1.
%H Seiichi Manyama, <a href="/A031353/b031353.txt">Table of n, a(n) for n = 1..10000</a>
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/MultiplicativePersistence.html">Multiplicative Persistence</a>
%K nonn,base
%O 1,2
%A _Eric W. Weisstein_
%E Offset 1 from _Seiichi Manyama_, Jan 13 2020