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 A258570 #17 Sep 12 2024 01:43:32
%S A258570 1,2,2,2,3,2,2,3,2,2,3,5,2,3,2,2,2,5,2,7,3,2,2,2,2,3,2,2,2,5,2,2,7,2,
%T A258570 2,2,11,3,2,2,2,2,2,2,13,2,5,2,2,2,2,2,3,2,2,2,2,3,2,7,2,2,2,2,2,2,2,
%U A258570 17,2,3,2,2,11,2,5,2,2,2,2,2,3,19,2,2,2
%N A258570 Smallest prime factors of 5-full numbers, a(1)=1.
%H A258570 Reinhard Zumkeller, <a href="/A258570/b258570.txt">Table of n, a(n) for n = 1..10000</a> (some terms corrected by Andrew Howroyd)
%F A258570 a(n) = A020639(A069492(n)).
%F A258570 a(A258602(n)) = A000040(n) and a(m) != A000040(n) for m < A258602(n).
%o A258570 (Haskell)
%o A258570 a258570 = a020639 . a069492
%o A258570 (PARI) lista(kmax) = {my(f); print1(1, ", "); for(k = 2, kmax, f = factor(k); if(vecmin(f[, 2]) > 4, print1(f[1, 1], ", "))); } \\ _Amiram Eldar_, Sep 12 2024
%Y A258570 Cf. A069492, A020639, A258602, A258567, A258568, A258569, A258571.
%K A258570 nonn
%O A258570 1,2
%A A258570 _Reinhard Zumkeller_, Jun 06 2015