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 A112755 #6 Feb 07 2020 09:03:47
%S A112755 1,3,5,3,3,5,3,3,3,3,5,3,3,3,3,3,5,3,3,3,3,3,3,3,5,3,3,3,3,3,3,3,3,5,
%T A112755 3,3,3,3,3,3,3,3,3,3,5,3,3,3,3,3,3,3,3,3,3,3,5,3,3,3,3,3,3,3,3,3,3,3,
%U A112755 3,3,5,3,3,3,3,3,3,3,3,3,3,3,3,3,3,5,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,5,3,3
%N A112755 Smallest prime factor of n-th number of the form 3^i*5^j.
%H A112755 Amiram Eldar, <a href="/A112755/b112755.txt">Table of n, a(n) for n = 1..10000</a>
%F A112755 a(n) = A020639(A003593(n));
%F A112755 a(n) <= A112756(n) <= 5.
%t A112755 s = {}; m = 12; Do[n = 5^k; While[n <= 5^m, AppendTo[s, n]; n *= 3], {k, 0, m}]; FactorInteger[#][[1, 1]] & /@ Union[s] (* _Amiram Eldar_, Feb 07 2020 *)
%Y A112755 Cf. A003593, A020639, A086410, A112756, A112763.
%K A112755 nonn
%O A112755 1,2
%A A112755 _Reinhard Zumkeller_, Sep 18 2005