A385160 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 points where circles intersect.
4, 68, 4244, 38100, 222300, 695544, 2252764
Offset: 1
Links
- Scott R. Shannon, Image for n = 2. The 4 x 2 = 8 starting points are shown as white dots.
- Scott R. Shannon, Image for n = 3. The 4 x 3 = 12 starting points are shown as white dots.
