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 A085819 #12 Jul 13 2021 06:24:24
%S A085819 1,2,6,12,60,420,4620,9240,27720,360360,6126120,116396280,2677114440,
%T A085819 77636318760,2406725881560,4813451763120,178097715235440,
%U A085819 7302006324653040,313986271960080720,14757354782123793840
%N A085819 a(n) = Product_{k<=n} A085818(k).
%C A085819 n divides a(n), see A085818.
%o A085819 (PARI) f(n) = 1 + sum(k=2, n, isprimepower(k) && !isprime(k)); \\ A085501
%o A085819 b(n) = {if (n==1, return (1)); my(p); if (isprimepower(n, &p) && !isprime(n), p, prime(n-f(n))); } \\ A085818
%o A085819 a(n) = prod(k=1, n, b(k)); \\ _Michel Marcus_, Jul 13 2021
%Y A085819 Cf. A000040, A000142, A002110, A085818.
%K A085819 nonn
%O A085819 1,2
%A A085819 _Reinhard Zumkeller_, Jul 04 2003