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 A380991 #14 Feb 12 2025 14:23:32 %S A380991 1,4,15,48 %N A380991 a(n) = largest number of cells of a polyomino with at most n collinear cell centers. %Y A380991 Cf. A378169, A380990. %K A380991 nonn,bref,hard,more %O A380991 1,2 %A A380991 _Dave Budd_, Feb 11 2025