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 A075198 #16 Jun 26 2021 03:57:29 %S A075198 1,1,2,5,9,24,41,121,213,522,783,2712,3179,8672,16621,37415,48558, %T A075198 154660,185007,573296,876633,1759730,2606543,8768743,10774339 %N A075198 Number of polyominoes with n cells that tile the plane by translation. %D A075198 Branko Grünbaum and G. C. Shephard, Tilings and Patterns. W. H. Freeman, New York, 1987, Section 9.4. %H A075198 Joseph Myers, <a href="http://www.polyomino.org.uk/mathematics/polyform-tiling/">Polyomino tiling</a> %e A075198 For n = 5, all 12 of the free pentominoes tile the plane by translation except for the R, T, and U pentominoes, so a(5) = 12 - 3 = 9. %Y A075198 Cf. A054359, A075199, A075200, A075201, A075202, A075203, A075204, A075205, A075206, A075207, A075216. %K A075198 hard,nonn %O A075198 1,3 %A A075198 _Joseph Myers_, Sep 08 2002 %E A075198 More terms from _Joseph Myers_, Nov 04 2003 %E A075198 a(24) and a(25) from _Joseph Myers_, Nov 17 2010