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 A359163 #8 Dec 17 2022 20:03:09 %S A359163 15,35,39,51,55,87,91,95,111,115,119,123,135,143,155,159,183,187,203, %T A359163 215,219,235,247,259,267,287,291,295,299,303,315,319,323,327,335,339, %U A359163 351,355,371,375,391,395,403,407,411,415,427,447,451,459,471,495,511,515,519,527,535,543,551,559,579,583 %N A359163 Numbers of the form 4u+3 with an even number of prime factors (counted with multiplicity). %e A359163 135 = 3 * 3 * 3 * 5 has an even number of prime factors and is of the form 4u+3, therefore 135 is included in this sequence. %o A359163 (PARI) isA359163(n) = A359162(n); %Y A359163 Intersection of A004767 and A028260. %Y A359163 Setwise difference A004767 \ A359153. %Y A359163 Setwise difference A046337 \ A359161. %Y A359163 Cf. A359162 (characteristic function). %Y A359163 Cf. A080774 (subsequence). %K A359163 nonn %O A359163 1,1 %A A359163 _Antti Karttunen_, Dec 17 2022