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 A009286 #15 May 26 2017 16:12:28 %S A009286 1,3,4,14,12,12,24,60,78,36,60,28,84,24,24,248,144,78,180,168,96,180, %T A009286 264,120,620,84,360,168,420,72,480,1008,240,432,48,1092,684,180,168, %U A009286 720,840,96,924,420,312,792,1104,496,798,1860,288,1176,1404,360,360,120,720,1260 %N A009286 a(n) = lcm(sigma(n), phi(n)). %H A009286 Antti Karttunen, <a href="/A009286/b009286.txt">Table of n, a(n) for n = 1..10000</a> %H A009286 <a href="/index/Lc#lcm">Index entries for sequences related to lcm's</a> %F A009286 From _Antti Karttunen_, May 26 2017: (Start) %F A009286 a(n) = A062354(n) / A009223(n). %F A009286 a(A000040(n)) = A084921(n). - after _Enrique Pérez Herrero_'s May 17 2012 comment in the latter sequence. %F A009286 (End) %o A009286 (PARI) A009286(n) = lcm(sigma(n), eulerphi(n)); \\ _Antti Karttunen_, May 26 2017 %Y A009286 Cf. A000010, A000203, A009223, A062354, A084921. %K A009286 nonn %O A009286 1,2 %A A009286 _David W. Wilson_