Place a point on the integer coordinates, up to |n|, along all four axial directions on a Cartesian plane, and then join a circle through every unordered triple of non-collinear points: a(n) is the number of distinct circles created.

A385159

Place a point on the integer coordinates, up to |n|, along all four axial directions on a Cartesian plane, and then join a circle through every unordered triple of non-collinear points: a(n) is the number of distinct circles created.

Terms

    a(0) =1a(1) =18a(2) =99a(3) =280a(4) =633a(5) =1098a(6) =1915a(7) =2928a(8) =4329a(9) =6010a(10) =8331a(11) =10752a(12) =14113a(13) =17778a(14) =21987

External references