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 A074389 #21 Sep 10 2018 05:00:35
%S A074389 1,1,1,1,1,2,1,1,1,2,1,4,1,2,1,1,1,3,1,2,1,2,1,4,1,2,1,4,1,2,1,1,1,2,
%T A074389 1,1,1,2,1,2,1,6,1,4,3,2,1,4,1,1,1,2,1,6,1,8,1,2,1,4,1,2,1,1,1,2,1,2,
%U A074389 1,2,1,3,1,2,1,4,1,6,1,2,1,2,1,4,1,2,1,4,1,6,1,4,1,2,1,4,1,1,3,1,1,2,1,2,3
%N A074389 a(n) = gcd(n, sigma(n), phi(n)).
%H A074389 Antti Karttunen, <a href="/A074389/b074389.txt">Table of n, a(n) for n = 1..65537</a>
%F A074389 a(n) = gcd(n, A000010(n), A000203(n)).
%F A074389 a(n) = gcd(n, A009223(n)). - _Antti Karttunen_, Sep 07 2018
%t A074389 Table[Apply[GCD, {w, DivisorSigma[1, w], EulerPhi[w]}], {w, 1, 128}]
%o A074389 (PARI) A074389(n) = gcd([n, sigma(n), eulerphi(n)]); \\ _Antti Karttunen_, Sep 07 2018
%Y A074389 Cf. A000010, A000203, A073815, A050399, A009194, A009195, A009223, A074465, A074466.
%Y A074389 In the old definition the erroneously given formula gcd(n, A000005(n), A000010(n)) is now sequence A318459. - _Antti Karttunen_, Sep 07 2018
%K A074389 nonn
%O A074389 1,6
%A A074389 _Labos Elemer_, Aug 23 2002
%E A074389 Name corrected by _Antti Karttunen_, Sep 07 2018