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 A348998 #13 Nov 13 2021 22:33:06
%S A348998 1,1,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,3,6,
%T A348998 3,6,1,2,3,6,3,6,1,2,3,6,3,6,1,2,3,6,3,6,1,2,3,6,3,6,1,2,3,6,9,18,1,2,
%U A348998 3,6,9,18,1,2,3,6,9,18,1,2,3,6,9,18,1,2,3,6,9,18,1,2,3,6,9,18,1,2,3,6,9,18
%N A348998 a(n) = A348928(A276086(n)), where A348928(n) = gcd(n, A003958(n)), and A003958 is multiplicative with a(p^e) = (p-1)^e, and A276086 gives the prime product form of primorial base expansion of n.
%C A348998 After each primorial number (A002110), the apparent periodicity grows more complex.
%H A348998 Antti Karttunen, <a href="/A348998/b348998.txt">Table of n, a(n) for n = 0..11550</a>
%H A348998 <a href="/index/Pri#primorialbase">Index entries for sequences related to primorial base</a>
%o A348998 (PARI) A348998(n) = { my(m1=1, m2=1, p=2); while(n, m1 *= (p^(n%p)); m2 *= ((p-1)^(n%p)); n = n\p; p = nextprime(1+p)); gcd(m1,m2); };
%Y A348998 Cf. A002110, A003958, A276086, A348928, A348999.
%K A348998 nonn,base,look
%O A348998 0,4
%A A348998 _Antti Karttunen_, Nov 07 2021