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 (finite) regions created.

A385161

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 (finite) regions created.

Terms

    a(0) =1a(1) =117a(2) =4713a(3) =41173a(4) =233365a(5) =725081a(6) =2323869

External references