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 A359153 #7 Jun 01 2025 15:22:58 %S A359153 3,7,11,19,23,27,31,43,47,59,63,67,71,75,79,83,99,103,107,127,131,139, %T A359153 147,151,163,167,171,175,179,191,195,199,207,211,223,227,231,239,243, %U A359153 251,255,263,271,275,279,283,307,311,331,343,347,359,363,367,379,383,387,399,419,423,431,435,439,443 %N A359153 Numbers of the form 4u+3 with an odd number of prime factors (counted with multiplicity). %t A359153 Select[4*Range[0,150]+3,OddQ[PrimeOmega[#]]&] (* _Harvey P. Dale_, Jun 01 2025 *) %o A359153 (PARI) isA359153(n) = A359152(n); %Y A359153 Intersection of A004767 and A026424. %Y A359153 Setwise difference A067019 \ A359151. %Y A359153 Setwise difference A004767 \ A359163. %Y A359153 Cf. A002145 (subsequence). %Y A359153 Cf. A359152 (characteristic function). %K A359153 nonn %O A359153 1,1 %A A359153 _Antti Karttunen_, Dec 17 2022