%I
%S 5,13,17,139,173,179,467,907,1553,1619,1867,2099,2819,2957,3203,3779,
%T 3947,4139,4157,4283,4547,4723,5483,6653,6899,7013,7187,7523,7643,
%U 8147,8387,8563,8573,8753,9533,9587,10589,10853,10883,10979,11003,12107,12227,13037,13229,13829,14243,14549,14699,14867,15299,16217,16547,16649,17387,18443,18587,19259
%N n such that A275391(n) = n2.
%C n such that n2 is the least k such that n divides A062727(k) = sigma(k^k).
%C Are all terms prime?
%e 17 is in the sequence because 17 divides sigma(15^15) = 821051025385244160 but does not divide sigma(k^k) for any k < 15.
%p N:= 20000:
%p S:= {$1..N}: # to get terms <= N
%p for kk from 1 while S <> {} do
%p v:= numtheory:sigma(kk^kk);
%p F:= select(t > v mod t = 0, S);
%p for nn in F do
%p B[nn]:= kk
%p od;
%p S:= S minus F;
%p od:
%p select(t > B[t]=t2, [$1..N]);
%Y Cf. A000203, A062727, A275391.
%K nonn
%O 1,1
%A _Robert Israel_, Aug 09 2016
