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.
%I A359933 #16 Apr 13 2023 02:35:20 %S A359933 45,836,8197,43252,167157,535572 %N A359933 Number of regions among all distinct circles that can be constructed from an n X n square grid of points using only a compass. %C A359933 A circle is constructed for every pair of the n X n points; the first point defines the circle's center while the second defines the radius. The number of distinct circles constructed from the n X n points is A359931(n). %C A359933 No formula for a(n) is known. %H A359933 Scott R. Shannon, <a href="/A359933/a359933.jpg">Image for n = 2</a>. In this and other images the n X n grid points are shown as white dots. %H A359933 Scott R. Shannon, <a href="/A359933/a359933_1.jpg">Image for n = 3</a>. %H A359933 Scott R. Shannon, <a href="/A359933/a359933_2.jpg">Image for n = 4</a>. %H A359933 Scott R. Shannon, <a href="/A359933/a359933_3.jpg">Image for n = 5</a>. %F A359933 a(n) = A359934(n) - A359932(n) + 1 by Euler's formula. %Y A359933 Cf. A359932 (vertices), A359934 (edges), A359935 (k-gons), A359931 (distinct circles), A359860, A359253. %K A359933 nonn,more %O A359933 2,1 %A A359933 _Scott R. Shannon_, Jan 21 2023