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 A328580 #12 Oct 20 2019 21:45:18
%S A328580 1,2,1,6,1,6,1,2,1,30,1,30,1,2,1,30,1,30,1,2,1,30,1,30,1,2,1,30,1,30,
%T A328580 1,2,1,6,1,6,1,2,1,210,1,210,1,2,1,210,1,210,1,2,1,210,1,210,1,2,1,
%U A328580 210,1,210,1,2,1,6,1,6,1,2,1,210,1,210,1,2,1,210,1,210,1,2,1,210,1,210,1,2,1,210,1,210
%N A328580 a(n) is the largest primorial dividing A276086(n), where A276086 converts the primorial base expansion of n into its prime product form.
%H A328580 Antti Karttunen, <a href="/A328580/b328580.txt">Table of n, a(n) for n = 0..2559</a>
%H A328580 <a href="/index/Pri#primorialbase">Index entries for sequences related to primorial base</a>
%F A328580 a(n) = A053589(A276086(n)).
%F A328580 a(n) = A002110(A328570(n)-1).
%F A328580 a(n) = A276086(n) / A328475(n).
%F A328580 a(n) = A276086(n) - A328476(n).
%F A328580 A328476(n) / a(n) = A328475(n) - 1.
%o A328580 (PARI) A328580(n) = { my(i=1, p=2, pr=1); while(n && (n%p), pr *= p; n = n\p; p = nextprime(1+p)); (pr); };
%Y A328580 Cf. A002110, A053589, A276086, A326810, A328475, A328476, A328570.
%K A328580 nonn
%O A328580 0,2
%A A328580 _Antti Karttunen_, Oct 20 2019