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 A333783 #24 Apr 09 2020 21:51:33 %S A333783 0,0,0,0,0,2,0,0,0,2,0,6,0,2,3,0,0,8,0,6,3,2,0,14,0,2,0,6,0,21,0,0,3, %T A333783 2,5,24,0,2,3,14,0,25,0,6,12,2,0,30,0,12,3,6,0,26,5,14,3,2,0,57,0,2, %U A333783 12,0,5,33,0,6,3,31,0,56,0,2,18,6,7,37,0,30,0,2,0,69,5,2,3,14,0,78,7,6,3,2,5,62,0,16,12 %N A333783 a(n) = sigma(n) - A332993(n). %C A333783 Sum of all other divisors of n, except those divisors that can be obtained by repeatedly taking the largest proper divisor (of previous such divisor, starting from n), up to and including the terminal 1. %H A333783 Antti Karttunen, <a href="/A333783/b333783.txt">Table of n, a(n) for n = 1..16384</a> %H A333783 Antti Karttunen, <a href="/A333783/a333783.txt">Data supplement: n, a(n) computed for n = 1..65537</a> %H A333783 <a href="/index/Si#SIGMAN">Index entries for sequences related to sigma(n)</a> %F A333783 a(n) = A000203(n) - A332993(n). %F A333783 a(n) = A001065(n) - A006022(n). %F A333783 a(n) = A333784(n) - A333791(n). %o A333783 (PARI) %o A333783 A332993(n) = if(1==n,n,n + A332993(n/vecmin(factor(n)[,1]))); %o A333783 A333783(n) = (sigma(n) - A332993(n)); %Y A333783 Cf. A000203, A000961 (positions of zeros), A001065, A006022, A032742, A332993, A333784, A333791. %K A333783 nonn,look %O A333783 1,6 %A A333783 _Antti Karttunen_, Apr 05 2020