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%I #4 Mar 30 2012 17:31:29
%S 1,10,13,23,19,7,356,4,2,11,15,5,3,14,45,36,6,112,269,15999
%N Smallest number that takes n steps to reach a cycle under iteration of sum-of-squares-of-digits map.
%F a(n) = minimum of either A001273(n) or A094406(n+3).
%t f[n_] := Plus @@ (IntegerDigits[n]^2); t = Table[0, {25}]; k = 1; While[k < 150000001, a = Length@ NestWhileList[f, k, UnsameQ@## &, All] - 1; If[a < 25 && t[[a]] == 0, t[[a]] = k; Print[{a, k}]]; k++ ]
%Y Cf. A001273, A094406, A045646, A003001.
%K nonn,base
%O 0,2
%A _Robert G. Wilson v_, Apr 25 2010
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