cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-3 of 3 results.

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.

Original entry on oeis.org

1, 18, 99, 280, 633, 1098, 1915, 2928, 4329, 6010, 8331, 10752, 14113, 17778, 21987
Offset: 1

Views

Author

Scott R. Shannon, Jun 20 2025

Keywords

Crossrefs

Cf. A385160 (vertices), A385161 (regions), A385162 (edges), A361622, A384700, A373110, A372735, A365669.

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.

Original entry on oeis.org

4, 68, 4244, 38100, 222300, 695544, 2252764
Offset: 1

Views

Author

Scott R. Shannon, Jul 10 2025

Keywords

Crossrefs

Cf. A385159 (total circles), A385161 (regions), A385162 (edges), A384703, A383461, A374825, A359569.

Formula

a(n) = A385162(n) - A385161(n) + 1 by Euler's formula.

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.

Original entry on oeis.org

4, 184, 8956, 79272, 455664, 1420624, 4576632
Offset: 1

Views

Author

Scott R. Shannon, Jul 10 2025

Keywords

Crossrefs

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

Formula

a(n) = A385160(n) + A385161(n) - 1 by Euler's formula.
Showing 1-3 of 3 results.