A139318 - OEIS

%I #9 Apr 09 2014 10:14:07

%S 1,1,2,1,2,2,4,2,2,3,2,3,4,3,4,6,6,4,10,2,6,3,2,8,4,3,4,4,2,5,10,8,6,

%T 4,2,5,4,6,4,6,2,5,4,2,6,3,6,7,4,5,6,6,2,3,6,5,8,4,12,7,6,6,6,7,2,6,4,

%U 6,4,7,8,6,4,3,8,10,6,7,4,5,6,9,2,8,12,5,4,4,2,6,10,5,12,7,6,6,4,9,10,7

%N a(n) = (A139317(n)-1)/n.

%e For A139317(7) we check: 7*1 +1= 8, which is not coprime to A139317(1)=2. 7*2 +1= 15, which is not coprime to either A139317(2)=3 or to A139317(4)=5. 7*3 +1 = 22, which is not coprime to either A139317(1)=2 or to A139317(5)=11. But 7*4+1 = 29, which is coprime to terms A139317(1) through A139317(6). So a(7) = 4.

%Y Cf. A139317, A139320.

%K nonn

%O 1,3

%A _Leroy Quet_, Apr 13 2008

%E More terms from _Max Alekseyev_, Apr 29 2011