a(n) = number of triangles with integer sides i <= j <= k with radius of circumcircle <= n.

Terms

a(0) =1a(1) =7a(2) =22a(3) =47a(4) =91a(5) =148a(6) =231a(7) =334a(8) =469a(9) =631a(10) =830a(11) =1062a(12) =1339a(13) =1657a(14) =2024a(15) =2434a(16) =2905a(17) =3427a(18) =4014a(19) =4653a(20) =5362a(21) =6141a(22) =6994a(23) =7911a(24) =8917a(25) =10000a(26) =11169a(27) =12425a(28) =13774a(29) =15211