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 A053457 #8 Mar 23 2022 12:18:09 %S A053457 0,0,2,6,12,16,26,38,48,60,78,94,108,128,154,174,196,224,250,278,312, %T A053457 344,378,410,452,484,526,574,612,652,698,754,800,848,906,958,1012, %U A053457 1068,1130,1190,1252,1316,1378,1446,1516,1588,1654,1730,1808,1880,1954 %N A053457 Open disk numbers (version 2): a(n) is the number of points (i,j), i,j, integers, contained in an open disk of diameter n, centered at (0,1/2). %C A053457 a(n)/(n/2)^2->Pi %Y A053457 Cf. A053414, A053456, A053458, A053459. %K A053457 easy,nonn %O A053457 0,3 %A A053457 Klaus Strassburger (strass(AT)ddfi.uni-duesseldorf.de), Jan 13 2000