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 A324646 #6 Mar 11 2019 20:47:54 %S A324646 1,2,3,2,1,6,1,2,3,10,1,6,1,2,15,2,1,18,1,10,3,2,1,6,25,2,3,2,1,30,1, %T A324646 2,3,2,7,18,1,2,3,10,1,42,1,2,15,2,1,6,7,50,3,2,1,18,5,14,3,2,1,30,1, %U A324646 2,21,2,1,6,1,2,3,70,1,18,1,2,75,2,7,6,1,10,3,2,1,42,5,2,3,2,1,90,7,2,3,2,1,6,1,98,3,10,1,6,1,2,105 %N A324646 a(n) = gcd(n, A276086(n-1)). %H A324646 Antti Karttunen, <a href="/A324646/b324646.txt">Table of n, a(n) for n = 1..30030</a> %H A324646 <a href="/index/Pri#primorialbase">Index entries for sequences related to primorial base</a> %H A324646 <a href="/index/Pri#primorial_numbers">Index entries for sequences related to primorial numbers</a> %F A324646 a(n) = gcd(n, A276086(n-1)). %F A324646 a(A002110(n)) = A002110(n) for all n >= 0. %o A324646 (PARI) %o A324646 A276086(n) = { my(i=0,m=1,pr=1,nextpr); while((n>0),i=i+1; nextpr = prime(i)*pr; if((n%nextpr),m*=(prime(i)^((n%nextpr)/pr));n-=(n%nextpr));pr=nextpr); m; }; %o A324646 A324646(n) = gcd(n,A276086(n-1)); %Y A324646 Cf. A002110, A276086, A324198, A324644. %K A324646 nonn %O A324646 1,2 %A A324646 _Antti Karttunen_, Mar 11 2019