Number of 3-element subsets of {1,...,n} whose sum has more than 2 divisors.

Terms

a(0) =0a(1) =0a(2) =1a(3) =3a(4) =8a(5) =14a(6) =25a(7) =38a(8) =58a(9) =83a(10) =118a(11) =158a(12) =210a(13) =268a(14) =339a(15) =417a(16) =510a(17) =611a(18) =728a(19) =855a(20) =1001a(21) =1158a(22) =1337a(23) =1529a(24) =1745a(25) =1973a(26) =2227a(27) =2495a(28) =2789a(29) =3098