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 A295310 #10 Nov 23 2017 12:28:10 %S A295310 1,2,1,2,1,2,1,8,3,2,1,12,1,2,1,2,1,6,1,4,1,2,1,8,5,2,1,4,1,6,1,4,1,2, %T A295310 1,36,1,2,3,8,1,2,1,4,3,2,1,12,1,10,3,2,1,2,1,8,1,2,1,12,1,2,3,2,1,6, %U A295310 1,4,1,2,1,24,1,2,15,4,1,6,1,20,1,2,1,12,1,2,1,8,1,18,1,4,1,2,1,24,1,2,3,20,1,6,1,8,1 %N A295310 a(n) = gcd(n, A062401(n)), where A062401(n) = phi(sigma(n)). %H A295310 Antti Karttunen, <a href="/A295310/b295310.txt">Table of n, a(n) for n = 1..16384</a> %F A295310 a(n) = gcd(n, A000010(A000203(n))). %t A295310 Array[GCD[#, EulerPhi[DivisorSigma[1, #]]] &, 105] (* _Michael De Vlieger_, Nov 23 2017 *) %o A295310 (PARI) a(n) = gcd(n, eulerphi(sigma(n))); \\ _Michel Marcus_, Nov 23 2017 %Y A295310 Cf. A000010, A000203, A062401, A295301, A295311, A295312, A295313. %K A295310 nonn %O A295310 1,2 %A A295310 _Antti Karttunen_, Nov 22 2017