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 A197463 #9 Jun 03 2022 11:17:08 %S A197463 2,3,6,13,28,66,148,349,828,2005,4880,12043,29852,74645,187498,473448, %T A197463 1199630,3050554,7778234,19885465,50950796,130824763,336555890, %U A197463 867389312,2239220294,5789804688 %N A197463 Number of one-sided poly-[4.6.12]-tiles (holes allowed) with n cells (division into triangles is significant). %D A197463 Branko Gruenbaum and G. C. Shephard, Tilings and Patterns. W. H. Freeman, New York, 1987, Sections 2.7, 6.2 and 9.4. %Y A197463 Cf. A197462, A197464. %K A197463 hard,nonn %O A197463 1,1 %A A197463 _Joseph Myers_, Oct 15 2011 %E A197463 a(20)-a(26) from _Aaron N. Siegel_, Jun 03 2022