A031182 - OEIS

%I #12 Apr 14 2020 03:30:10

%S 1,1,7,7,7,7,7,7,7,7,1,7,1,7,7,7,7,1,7,7,7,1,7,7,7,7,7,7,7,7,7,7,7,7,

%T 7,7,7,7,7,7,7,7,7,7,7,7,1,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,1,7,2,7,

%U 7,7,7,1,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7

%N Periods of sum of fourth 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 14 2020