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 A210988 #10 Feb 16 2025 08:33:17 %S A210988 1,7,60,704,9189,126759,1802312,26152418,385221143,5741256764, %T A210988 86383382827,1309998125640,19998172734786,307022182222506, %U A210988 4736694001644862,73390033697855860,1141388483146794007,17810678207278478530 %N A210988 Number of one-sided polyominoes with 2n cells. %C A210988 Sequence related with polydominoes and other similar sequences. It appears that we can write A216492(n) < A216583(n) < A056785(n) < A056786(n) < A210996(n) < a(n) < A210986(n), if n >= 3. - _Omar E. Pol_, Sep 16 2012 %H A210988 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Polyomino.html">Polyomino</a> %H A210988 Wikipedia, <a href="http://en.wikipedia.org/wiki/Polyomino">Polyomino</a> %Y A210988 Bisection of A000988. %Y A210988 Cf. A210989, A210996. %K A210988 nonn %O A210988 1,2 %A A210988 _Omar E. Pol_, Sep 16 2012