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 A057783 #11 Jul 02 2022 04:14:39 %S A057783 1,6,74,1257,25379,544108,12037738 %N A057783 Building block is 2 hexagons side-by-side; sequence gives number of pieces (polydohexes) that can be formed from n such pairs of hexagons. %D A057783 Computed by Brendan Owen. %H A057783 Andrew Clarke, <a href="http://www.recmath.com/PolyPages/PolyPages/PolyX/index.htm?PolyX.htm">Other Polyforms</a> %H A057783 Sean A. Irvine, <a href="https://github.com/archmageirvine/joeis/blob/master/src/irvine/oeis/a057/A057783.java">Java program</a> (github) %Y A057783 Cf. A000228, A000105, A000665. %K A057783 nonn,hard,more,nice %O A057783 1,2 %A A057783 _N. J. A. Sloane_, Oct 29 2000 %E A057783 Link updated by _William Rex Marshall_, Dec 16 2009 %E A057783 a(7) from _Sean A. Irvine_, Jul 02 2022