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 A373833 #13 Jun 21 2024 07:47:55
%S A373833 0,1,1,1,2,1,1,1,2,3,1,1,2,1,1,1,4,1,3,1,4,1,1,1,4,5,1,3,2,1,1,1,2,3,
%T A373833 1,1,2,1,1,1,4,1,3,1,4,5,1,1,4,1,5,3,2,1,1,1,2,1,1,1,2,1,1,1,4,5,3,1,
%U A373833 4,1,5,1,4,1,1,3,2,7,1,1,2,1,1,1,6,1,1,1,8,1,3,1,4,1,1,1,4,1,1,3,2,1,1,1,2,7
%N A373833 a(n) = gcd(n, A276150(n)), where A276150 is the digit sum in the primorial base.
%H A373833 Antti Karttunen, <a href="/A373833/b373833.txt">Table of n, a(n) for n = 0..100000</a>
%H A373833 <a href="/index/Pri#primorialbase">Index entries for sequences related to primorial base</a>
%F A373833 a(n) = A373835(A276086(n)).
%F A373833 For n >= 1, a(n) = gcd(A276150(n), A373832(n)).
%o A373833 (PARI)
%o A373833 A276150(n) = { my(s=0, p=2, d); while(n, d = (n%p); s += d; n = (n-d)/p; p = nextprime(1+p)); (s); };
%o A373833 A373833(n) = gcd(n, A276150(n));
%Y A373833 Cf. A049345, A276086, A276150, A333426 [positive k for which a(k) = A276150(k)], A358977 (indices of 1's), A373832, A373834, A373835, A373838, A373839 (indices of multiples of 3).
%K A373833 nonn,base
%O A373833 0,5
%A A373833 _Antti Karttunen_, Jun 19 2024