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 A358767 #6 Dec 19 2022 15:07:05 %S A358767 1,3,5,8,13,14,15,18,22,23,24,27,28,34,36,37,38,39,40,42,44,49,50,53, %T A358767 58,59,61,62,63,65,66,68,69,70,73,76,77,81,82,83,84,86,89,90,94,99, %U A358767 100,102,103,104,110,111,112,114,115,116,119,120,121,124,125,131,132,133,134,135,139,140,142,144 %N A358767 Numbers k with an even number of prime factors (when counted with multiplicity) in sigma(k), the sum of divisors of k. %H A358767 <a href="/index/O#opnseqs">Index entries for sequences where odd perfect numbers must occur, if they exist at all</a> %H A358767 <a href="/index/Si#SIGMAN">Index entries for sequences related to sigma(n)</a> %o A358767 (PARI) isA358767(n) = !(bigomega(sigma(n))%2); %Y A358767 Positions of even terms in A058063. Positions of 1's in A358766. %Y A358767 Cf. A000203, A001222, A358768 (complement). %Y A358767 Cf. also A359167, A359168. %K A358767 nonn %O A358767 1,2 %A A358767 _Antti Karttunen_, Dec 19 2022