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 A368999 #5 Jan 14 2024 15:06:44 %S A368999 2,3,5,6,7,8,10,11,13,14,17,18,19,22,23,24,26,27,29,30,31,32,34,37,38, %T A368999 40,41,42,43,45,46,47,50,53,54,56,58,59,61,62,63,66,67,70,71,72,73,74, %U A368999 75,78,79,82,83,86,88,89,90,94,96,97,98,99,101,102,103,104,105,106,107,109,110,113,114,117,118,120,122,125 %N A368999 Numbers k for which A342001(k) is odd. %o A368999 (PARI) %o A368999 A003415(n) = if(n<=1, 0, my(f=factor(n)); n*sum(i=1, #f~, f[i, 2]/f[i, 1])); %o A368999 A003557(n) = (n/factorback(factorint(n)[, 1])); %o A368999 A342001(n) = (A003415(n) / A003557(n)); %o A368999 isA368999(n) = (A342001(n)%2); %Y A368999 Cf. A342001. %Y A368999 Positions of 0's in A368997. Cf. A368999 (complement). %K A368999 nonn %O A368999 1,1 %A A368999 _Antti Karttunen_, Jan 14 2024