This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A175232 #7 Feb 04 2020 03:57:58
%S A175232 5,2,2,3413,50069,2,2,7,10405071317,2,2,88799,3,2,2,3,3,2,2,5,3,2,2,3,
%T A175232 7,2,2,7,208492413443704093346554910065262730566475781,2,2,3,17,2,2,5,
%U A175232 61,2,2,71,11,2,2,11,7,2,2,5,3,2,2,3,3,2,2,23,3,2,2,3,44818693,2,2,5
%N A175232 The smallest prime divisor of 1 + 2^2 + 3^3 + ... + n^n.
%F A175232 a(n) = A020639(A001923(n)).
%e A175232 a(2) = 5 divides 1 + 2^2.
%e A175232 a(3) = 2 divides 1 + 2^2 + 3^3 = 32.
%e A175232 a(4) = 2 divides 1 + 2^2 + 3^3 + 4^4 = 288.
%e A175232 a(5) = 3413 divides 1 + 2^2 + 3^3 + 4^4 + 5^5 = 3413.
%e A175232 a(13) = 88799 divides 1 + 2^2 + 3^3 + ... + 13^13 = 88799 * 3514531963.
%p A175232 with(numtheory): s :=1: for n from 2 to 60 do ;s := s+ n^n: s1 := ifactors(s)[2] : s2 :=s1[i][1], i=1..nops(s1):print(s1[1][1]):od:
%t A175232 a[n_] := FactorInteger[Sum[k^k, {k, 1, n}]][[1, 1]]; Array[a, 20, 2] (* _Amiram Eldar_, Feb 04 2020 *)
%Y A175232 Cf. A073826, A122166.
%K A175232 nonn
%O A175232 2,1
%A A175232 _Michel Lagneau_, Mar 09 2010
%E A175232 Edited by _R. J. Mathar_, Mar 16 2010
%E A175232 a(61)-a(65) from _Amiram Eldar_, Feb 04 2020