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 A339966 #9 Jan 07 2023 13:05:48 %S A339966 2,1,1,5,1,7,1,3,10,11,1,13,1,5,2,17,1,19,1,1,11,23,1,5,26,9,7,29,1, %T A339966 31,1,11,17,35,3,37,1,13,5,41,1,43,1,15,23,47,1,49,50,17,13,53,1,11,7, %U A339966 19,29,59,1,61,1,21,8,65,11,67,1,23,35,71,1,73,1,25,19,11,13,79,1,27,82,83,1,85,43,29,11,89,1,7 %N A339966 a(n) = (n+1) / gcd(sigma(n),n+1). %H A339966 Antti Karttunen, <a href="/A339966/b339966.txt">Table of n, a(n) for n = 1..65537</a> %H A339966 <a href="/index/Si#SIGMAN">Index entries for sequences related to sigma(n)</a> %F A339966 a(n) = (n+1) / A339964(n). %F A339966 a(n) = denominator(sigma(n)/(n+1)). - _Michel Marcus_, Jan 07 2023 %o A339966 (PARI) A339966(n) = (n+1)/(gcd(sigma(n),n+1)); %Y A339966 Cf. A000203, A339964, A339965 (numerators). %Y A339966 Cf. A017666. %Y A339966 Cf. also A160596. %K A339966 nonn,frac %O A339966 1,1 %A A339966 _Antti Karttunen_, Dec 25 2020