Number of triples (i,j,k) with 1 <= i < j < k <= n and gcd(i,j,k) = 1.

Terms

a(0) =0a(1) =0a(2) =1a(3) =4a(4) =10a(5) =19a(6) =34a(7) =52a(8) =79a(9) =109a(10) =154a(11) =196a(12) =262a(13) =325a(14) =409a(15) =493a(16) =613a(17) =712a(18) =865a(19) =997a(20) =1171a(21) =1336a(22) =1567a(23) =1747a(24) =2017a(25) =2251a(26) =2548a(27) =2818a(28) =3196a(29) =3472