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 A075201 #12 Dec 05 2014 03:05:24 %S A075201 0,0,0,0,3,11,60,199,748,2181,5391,17193,31881,85942,218760,430339, %T A075201 728315,2344106,3096983,9344528,17859116,31658109,49644736,172596719, %U A075201 228795554 %N A075201 Number of polyominoes with n cells that tile the plane by 180-degree rotation (Conway criterion) but not by translation. %D A075201 Branko Grünbaum and G. C. Shephard, Tilings and Patterns. W. H. Freeman, New York, 1987, Section 9.4. %H A075201 Joseph Myers, <a href="http://www.polyomino.org.uk/mathematics/polyform-tiling/">Polyomino tiling</a> %Y A075201 Cf. A054359, A075198, A075199, A075200, A075202, A075203, A075204, A075205, A075206, A075210, A075219. %K A075201 hard,nonn %O A075201 1,5 %A A075201 _Joseph Myers_, Sep 08 2002 %E A075201 More terms from _Joseph Myers_, Nov 04 2003 %E A075201 a(24) and a(25) from _Joseph Myers_, Nov 17 2010