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 A344999 #6 Jun 07 2021 06:50:00 %S A344999 -1,0,-4,9,-18,60,-40,33,4,90,-108,240,-154,120,48,93,-270,288,-340, %T A344999 468,0,180,-504,672,-54,210,52,768,-810,3096,-928,237,-192,270,-480, %U A344999 948,-1330,300,-336,1404,-1638,5088,-1804,1584,648,360,-2160,1680,-216,684,-720,2100,-2754,1116,-1584,2400,-960,450,-3420,10080 %N A344999 a(n) = A048250(n) * A345001(n). %F A344999 a(n) = A048250(n) * A345001(n). %F A344999 a(n) = A344998(n) - A345043(n). %o A344999 (PARI) %o A344999 A003415(n) = if(n<=1, 0, my(f=factor(n)); n*sum(i=1, #f~, f[i, 2]/f[i, 1])); %o A344999 A048250(n) = factorback(apply(p -> p+1,factor(n)[,1])); %o A344999 A345001(n) = (sigma(n)+A003415(n)-(2*n)); %o A344999 A344999(n) = (A048250(n) * A345001(n)); %Y A344999 Cf. A000203, A003415, A048250, A345001. %Y A344999 Cf. A345003 [gives k for which a(k) = A344998(k)], A345004, A345005. %K A344999 sign %O A344999 1,3 %A A344999 _Antti Karttunen_, Jun 05 2021