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 A054642 #8 Oct 26 2019 02:05:21
%S A054642 1,6,42,210,3990,43890,1360590,23130030,855811110,11125544430,
%T A054642 255887521890,20215114229310,828819683401710,24035770818649590,
%U A054642 2331469769409010230,123567897778677542190,5313419604483134314170
%N A054642 Distinct values of GCD of divisor sum of primorials and primorial itself: gcd(A002110(n), A000203(A002110(n))).
%C A054642 Below n=100, 30 values arise and if large enough are divisible by large primorials. E.g., for n=1..30, a(n) mod 510510 = {1, 6, 42, 210, 3990, 43890, 339570, 157080, 196350, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}.
%Y A054642 Cf. A000203, A002110, A054640, A054641.
%K A054642 nonn
%O A054642 1,2
%A A054642 _Labos Elemer_, May 15 2000