A144764 - OEIS

%I #2 Mar 31 2012 10:28:53

%S 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 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 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 Partial totient function phi(c, n) for c = 3: number of 3-semiprimes less than and coprime to n.

%Y Cf. A000010, A014612, A144740

%Y Cf. A036997 (phi(n) - max(phi(c, n)) over all nonnegative integers c)

%K easy,nonn

%O 1,13

%A _Reikku Kulon_, Sep 20 2008