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 A009242 #21 Mar 27 2024 09:00:11 %S A009242 1,6,12,28,30,12,56,120,117,90,132,84,182,168,120,496,306,234,380,420, %T A009242 672,396,552,120,775,546,1080,56,870,360,992,2016,528,918,1680,3276, %U A009242 1406,1140,2184,360,1722,672,1892,924,1170,1656,2256,1488,2793,4650,1224,2548 %N A009242 a(n) = lcm(n, sigma(n)). %H A009242 Amiram Eldar, <a href="/A009242/b009242.txt">Table of n, a(n) for n = 1..10000</a> %F A009242 a(n) = n*A017665(n). - _Enrique Pérez Herrero_, Aug 25 2011 %F A009242 a(n) = A064987(n)/A009194(n). - _Amiram Eldar_, Mar 27 2024 %t A009242 A009242[n_]:=LCM[DivisorSigma[1,n],n]; Array[A009242,100] (* _Enrique Pérez Herrero_, Aug 25 2011 *) %o A009242 (PARI) a(n) = lcm(n, sigma(n)); \\ _Amiram Eldar_, Mar 27 2024 %Y A009242 Cf. A009194, A017665, A064987. %K A009242 nonn,easy %O A009242 1,2 %A A009242 _David W. Wilson_