A126090 - OEIS

%I #9 Apr 09 2014 10:13:42

%S 1,1,2,2,4,3,6,3,5,5,10,6,12,7,8,5,16,8,18,13,7,11,22,10,17,14,18,16,

%T 28,9,30,11,12,20,11,16,36,22,12,23,40,14,42,28,19,29,46,22,39,28,15,

%U 33,52,28,16,29,17,36,58,20,60,38,25,22,15,23,66,43,23,20,70,37,72,45

%N a(1)=1. a(n) = the number of terms among {a(1),a(2),...a(n-1)} which are coprime to exactly one distinct prime dividing n.

%H Diana Mecum, <a href="/A126090/b126090.txt">Table of n, a(n) for n = 1..500</a>

%e There are 6 terms among the first 11 terms of the sequence which are each coprime to exactly one distinct prime dividing 12 (a(3)=2, a(4)=2, a(5)=4, a(6)=3, a(8)=3 and a(11)=10). So a(12) = 6.

%Y Cf. A126080.

%K nonn

%O 1,3

%A _Leroy Quet_, Mar 03 2007

%E More terms from _Diana L. Mecum_, Jun 23 2007