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 A112752 #8 Feb 06 2020 07:27:44
%S A112752 1,1,1,3,5,1,9,15,3,1,5,45,9,3,15,5,25,27,9,45,15,75,81,1,125,135,45,
%T A112752 225,243,3,375,405,5,625,675,729,9,1125,1215,15,1875,2025,2187,1,3125,
%U A112752 3375,3645,45,5625,6075,6561,3,9375,10125,10935,5,15625,16875,18225
%N A112752 Greatest common divisors of consecutive terms of numbers of the form 3^i*5^j.
%H A112752 Amiram Eldar, <a href="/A112752/b112752.txt">Table of n, a(n) for n = 1..10000</a>
%F A112752 a(n) = gcd(A003593(n), A003593(n+1)).
%t A112752 s = {}; m = 12; Do[n = 5^k; While[n <= 5^m, AppendTo[s, n]; n *= 3], {k, 0, m}]; Map[GCD @@ # &, Partition[Union[s], 2, 1]] (* _Amiram Eldar_, Feb 06 2020 *)
%Y A112752 Cf. A003593, A112757.
%K A112752 nonn
%O A112752 1,4
%A A112752 _Reinhard Zumkeller_, Sep 18 2005