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 A291806 #18 Sep 11 2017 10:31:05 %S A291806 1,5,216,212987 %N A291806 The number of polyomino tilings of n X n square. %C A291806 The sequence gives the number of distinct tilings by polyominoes of a square with side n. As for "free" polyominoes, tilings that are reflections or rotations of each other are not considered distinct. %C A291806 Using the same terminology used for polyominoes: the corresponding sequence for "fixed" tilings is 1,12,1434,1691690, and for one-sided tilings is 1,5,222,213315. %H A291806 John Mason, <a href="/A291806/a291806.pdf">Tiling examples</a> %Y A291806 Cf. A268416 (polyominoes that will fit in n-sided square), A291807 (symmetric tilings), A291808 (tilings with distinct polyominoes), A291809 (tilings with differently sized polyominoes). %K A291806 nonn,more %O A291806 1,2 %A A291806 _John Mason_, Sep 01 2017