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 A144765 #12 Apr 15 2023 05:17:42 %S A144765 0,0,0,0,0,0,0,1,0,1,0,2,0,2,1,2,0,3,0,4,2,4,0,4,1,4,3,5,0,7,0,6,4,6, %T A144765 3,7,0,6,4,6,0,8,0,8,7,8,0,10,2,10,6,10,0,12,5,10,6,10,0,12,0,10,8,10, %U A144765 5,14,0,12,8,15,0,16,0,13,12,14,6,19,0,17,10,15,0,19,7,15,10,15,0,19,6,16 %N A144765 Number of triprimes less than or equal to and not coprime to n. %o A144765 (PARI) a(n) = sum(k=1, n, if (bigomega(k) == 3, gcd(k,n) != 1)); \\ _Michel Marcus_, Apr 15 2023 %Y A144765 Cf. A000010, A014612, A144741. %K A144765 easy,nonn %O A144765 1,12 %A A144765 _Reikku Kulon_, Sep 20 2008