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

Terms

a(0) =0a(1) =1a(2) =4a(3) =9a(4) =19a(5) =30a(6) =51a(7) =73a(8) =106a(9) =140a(10) =195a(11) =241a(12) =319a(13) =388a(14) =480a(15) =572a(16) =708a(17) =813a(18) =984a(19) =1124a(20) =1310a(21) =1485a(22) =1738a(23) =1926a(24) =2216a(25) =2462a(26) =2777a(27) =3059a(28) =3465a(29) =3749