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 A074592 #9 Oct 10 2024 08:17:30
%S A074592 2,2,2,2,3,2,2,3,2,2,2,2,2,3,2,5,2,2,3,2,2,2,3,2,2,2,3,2,2,5,2,3,2,2,
%T A074592 2,3,5,2,2,3,2,2,2,3,2,7,2,2,2,2,5,2,3,2,2,7,2,3,2,5,2,2,3,2,2,2,3,2,
%U A074592 2,2,3,2,2,5,2,3,2,7,2,2,3,2,2,3,2,2,7,2,3,2,2,2,3,2,11,2,5,2,3,2,2,2,3,2
%N A074592 Smallest prime factors of numbers that are not prime powers.
%H A074592 Amiram Eldar, <a href="/A074592/b074592.txt">Table of n, a(n) for n = 1..10000</a>
%F A074592 a(n) = A020639(A024619(n)).
%F A074592 a(n) > 2 iff n+1 and n+2 are prime powers (A006549).
%t A074592 s[n_] := Module[{f = FactorInteger[n]}, If[Length[f] > 1, f[[1, 1]], Nothing]]; Array[s, 200] (* _Amiram Eldar_, Oct 10 2024 *)
%Y A074592 Cf. A006549, A020639, A024619, A074593, A074594, A074595.
%K A074592 nonn
%O A074592 1,1
%A A074592 _Reinhard Zumkeller_, Aug 25 2002