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 A197460 #14 May 16 2022 02:35:11 %S A197460 1,1,4,6,19,49,143,403,1235,3681,11354,34944,108956,340635,1072593, %T A197460 3388161,10751029,34217608,109255023,349750874,1122436127,3610017340 %N A197460 Number of one-sided poly-[3.6.3.6]-tiles (holes allowed) with n cells (division into rhombi is significant). %D A197460 Branko Grünbaum and G. C. Shephard, Tilings and Patterns. W. H. Freeman, New York, 1987, Sections 2.7, 6.2 and 9.4. %Y A197460 Cf. A197459, A197461. %K A197460 nonn,hard,more %O A197460 1,3 %A A197460 _Joseph Myers_, Oct 15 2011 %E A197460 a(18)-a(22) from _Aaron N. Siegel_, May 15 2022