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 A056755 #11 Jul 02 2025 16:02:00 %S A056755 2,10,68,609,5652 %N A056755 Number of n-celled polyominoes, where the cells are 1 X 2 rectangles with some of the edges of length 2 replaced by curved arcs that either sag inwards or bulge outwards. %C A056755 The rules that govern which edges are changed are not completely clear, so two examples drawn by M. Vicher have been included. %C A056755 Probably an erroneous version of A121194. %C A056755 Row 11 of polyforms table, puzzle 1 (See link). - Omar E. Pol, Feb 22 2011. %H A056755 M. Vicher, <a href="http://www.vicher.cz/puzzle/polyforms.htm">Polyforms</a> %H A056755 M. Vicher, <a href="http://www.vicher.cz/puzzle/polyform/new1/images/b1.gif">The 10 2-celled polyominoes</a> %H A056755 M. Vicher, <a href="/A056755/a056755a.gif">The 10 2-celled polyominoes</a> %H A056755 M. Vicher, <a href="http://www.vicher.cz/puzzle/polyform/new1/images/p6.gif">The 68 3-celled polyominoes</a> %H A056755 M. Vicher, <a href="/A056755/a056755b.gif">The 68 3-celled polyominoes</a> %Y A056755 Cf. A121194. %K A056755 nonn,obsc %O A056755 1,1 %A A056755 _James Sellers_, Aug 28 2000 %E A056755 Edited by _N. J. A. Sloane_, Jun 21 2001