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 A144764 #2 Mar 31 2012 10:28:53 %S A144764 0,0,0,0,0,0,0,0,1,0,1,0,2,0,1,0,2,0,3,0,2,0,4,0,3,0,2,1,6,0,7,1,3,1, %T A144764 4,0,7,1,3,1,7,0,8,1,3,2,10,0,8,1,5,2,12,0,7,2,6,2,12,0,12,2,5,3,8,0, %U A144764 14,3,7,1,16,0,16,3,5,4,12,0,19,2,9,4,19,0,12,4,9,4,19,0,13,4,10,4,13,0,20,3 %N A144764 Partial totient function phi(c, n) for c = 3: number of 3-semiprimes less than and coprime to n. %Y A144764 Cf. A000010, A014612, A144740 %Y A144764 Cf. A036997 (phi(n) - max(phi(c, n)) over all nonnegative integers c) %K A144764 easy,nonn %O A144764 1,13 %A A144764 _Reikku Kulon_, Sep 20 2008