A385162 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 (curved) edges formed from the intersections of the circles.

4, 184, 8956, 79272, 455664, 1420624, 4576632

Offset

1,1

Links

Table of n, a(n) for n=1..7.

Scott R. Shannon, Image for n = 2. The 4 x 2 = 8 starting points are shown as white dots.

Formula

a(n) = A385160(n) + A385161(n) - 1 by Euler's formula.

Crossrefs

Cf. A385159 (total circles), A385160 (vertices), A385161 (regions), A384703, A374827, A373108, A359571.

Sequence in context: A221046 A024266 A174772 * A146549 A156905 A202631

Adjacent sequences: A385159 A385160 A385161 * A385163 A385164 A385165

Keyword

nonn,more

Author

Scott R. Shannon, Jul 10 2025

Status

approved