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 A258571 #14 Sep 12 2024 01:43:41
%S A258571 1,2,2,2,2,3,2,2,3,2,3,2,5,2,3,2,2,3,2,5,2,7,2,2,3,2,2,2,2,5,2,2,3,2,
%T A258571 2,7,2,2,2,2,2,2,3,2,11,5,2,2,2,2,2,2,2,2,2,2,3,13,2,2,7,2,2,2,2,2,2,
%U A258571 2,5,2,2,2,3,2,2,3,2,2,2,2,2,11,2,2,2
%N A258571 Smallest prime factors of 6-full numbers, a(1)=1.
%H A258571 Andrew Howroyd, <a href="/A258571/b258571.txt">Table of n, a(n) for n = 1..10000</a> (terms 1..191 from Reinhard Zumkeller)
%F A258571 a(n) = A020639(A069493(n)).
%F A258571 a(A258603(n)) = A000040(n) and a(m) != A000040(n) for m < A258603(n).
%o A258571 (Haskell)
%o A258571 a258571 = a020639 . a069493
%o A258571 (PARI) lista(kmax) = {my(f); print1(1, ", "); for(k = 2, kmax, f = factor(k); if(vecmin(f[, 2]) > 5, print1(f[1, 1], ", "))); } \\ _Amiram Eldar_, Sep 12 2024
%Y A258571 Cf. A069493, A020639, A258603, A258567, A258568, A258569, A258570.
%K A258571 nonn
%O A258571 1,2
%A A258571 _Reinhard Zumkeller_, Jun 06 2015