Number of ordered triples (a, b, c) with gcd(a, b, c) = 1 and 1 <= {a, b, c} <= n.

Terms

a(0) =1a(1) =7a(2) =25a(3) =55a(4) =115a(5) =181a(6) =307a(7) =439a(8) =637a(9) =841a(10) =1171a(11) =1447a(12) =1915a(13) =2329a(14) =2881a(15) =3433a(16) =4249a(17) =4879a(18) =5905a(19) =6745a(20) =7861a(21) =8911a(22) =10429a(23) =11557a(24) =13297a(25) =14773a(26) =16663a(27) =18355a(28) =20791a(29) =22495