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 A355037 #15 Feb 13 2025 13:08:02
%S A355037 0,1,0,1,0,2,0,0,0,1,0,2,0,0,0,2,0,4,0,0,0,3,0,6,0,0,0,4,0,8,0,0,0,0,
%T A355037 0,0,0,0,0,1,0,2,0,0,0,2,0,4,0,0,0,3,0,6,0,0,0,4,0,8,0,0,0,0,0,0,0,0,
%U A355037 0,2,0,4,0,0,0,4,0,8,0,0,0,6,0,12,0,0,0
%N A355037 a(n) is the product of the digits of n in primorial base.
%H A355037 Rémy Sigrist, <a href="/A355037/b355037.txt">Table of n, a(n) for n = 0..10000</a>
%H A355037 <a href="/index/Pri#primorialbase">Index entries for sequences related to primorial base</a>
%F A355037 a(n) = 1 iff n belongs to A143293.
%F A355037 a(n) > 0 iff n belongs to A328574 \ {0}.
%e A355037 The first terms, alongside the digits of n in primorial base, are:
%e A355037 n a(n) pr(n)
%e A355037 -- ---- -----
%e A355037 0 0 0
%e A355037 1 1 1
%e A355037 2 0 1_0
%e A355037 3 1 1_1
%e A355037 4 0 2_0
%e A355037 5 2 2_1
%e A355037 6 0 1_0_0
%e A355037 7 0 1_0_1
%e A355037 8 0 1_1_0
%e A355037 9 1 1_1_1
%e A355037 10 0 1_2_0
%e A355037 11 2 1_2_1
%e A355037 12 0 2_0_0
%e A355037 13 0 2_0_1
%e A355037 14 0 2_1_0
%e A355037 15 2 2_1_1
%o A355037 (PARI) a(n) = { my (p=1); forprime (r=2, oo, p*=n%r; n\=r; if (p==0 || n==0, return (p))) }
%Y A355037 Cf. A143293, A208575, A235168, A328574, A328581.
%K A355037 nonn,look,base
%O A355037 0,6
%A A355037 _Rémy Sigrist_, Jun 16 2022