Number of line segments connecting exactly 3 points in an n X n grid of points.

Terms

a(0) =0a(1) =0a(2) =8a(3) =24a(4) =60a(5) =112a(6) =212a(7) =344a(8) =548a(9) =800a(10) =1196a(11) =1672a(12) =2284a(13) =2992a(14) =3988a(15) =5128a(16) =6556a(17) =8160a(18) =10180a(19) =12424a(20) =15068a(21) =17968a(22) =21604a(23) =25576a(24) =30092a(25) =34976a(26) =40900a(27) =47288a(28) =54500a(29) =62224