%I #12 Apr 16 2020 01:23:04
%S 1,1,17,123,17,17,123,123,123,123,1,17,123,17,123,123,123,81,81,123,
%T 17,123,123,123,123,123,123,123,123,123,123,17,123,123,123,123,123,81,
%U 17,123,17,123,123,123,123,123,7,123,123,123,17,123,123,123,123
%N Periods of sum of 10th powers of digits iterated until the sequence becomes periodic.
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/Digitaddition.html">Digitaddition</a>
%K nonn,base
%O 0,3
%A _Eric W. Weisstein_
%E Missing a(0)=1 inserted by _Sean A. Irvine_, Apr 15 2020