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 A068502 #18 May 14 2022 11:30:24 %S A068502 10,12,14,22,26,34,35,38,42,44,45,46,56,58,62,65,70,74,76,77,78,82,85, %T A068502 86,92,94,99,105,106,114,115,118,119,122,124,130,133,134,142,143,146, %U A068502 154,158,161,166,168,170,172,178,184,185,186,187,188,194,195,202,206 %N A068502 Composite numbers k such that gcd(sigma(k), k) = gcd(k, phi(k)). %H A068502 Amiram Eldar, <a href="/A068502/b068502.txt">Table of n, a(n) for n = 1..10000</a> %t A068502 Cases[Range[2, 206], n_ /; !PrimeQ[n] && GCD[Total[Divisors[n]], n] == GCD[n, EulerPhi[n]]] (* _Jean-François Alcover_, Mar 15 2011 *) %t A068502 fQ[n_]:=!PrimeQ[n]&&GCD[Total[Divisors[n]],n] == GCD[n,EulerPhi[n]];Select[Range[2,206],fQ] (* _Zak Seidov_, Mar 15 2011 *) %Y A068502 Cf. A000010, A000203, A009194, A009195. %K A068502 easy,nonn %O A068502 1,1 %A A068502 _Benoit Cloitre_, Mar 11 2002