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 A338212 #7 Oct 18 2020 06:04:44 %S A338212 1,0,0,0,0,1,0,0,2,0,4,2,9,9,22,32,66,104,200,348,646,1172,2144,3964, %T A338212 7285,13581,25136,47070,87700,164764,309308,582152,1098698,2074484 %N A338212 a(n) is the number of fixed polyominoes with sprawl n. %C A338212 The sprawl of a polyomino is the number of cells in a polyomino plus the number of cells adjacent to it. %H A338212 Sean A. Irvine, <a href="https://github.com/archmageirvine/joeis/blob/master/src/irvine/oeis/a338/A338212.java">Java program</a> (github) %F A338212 Antidiagonal sums of A338210. %Y A338212 Cf. A001168, A338210, A338213. %K A338212 nonn,more %O A338212 0,9 %A A338212 _Sean A. Irvine_ and _Allan C. Wechsler_, Oct 17 2020