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 A226543 #7 Aug 25 2013 17:10:52 %S A226543 1,1,55,595,11012,168925,2760690,44159095,711479843,11435477118, %T A226543 183947396032,2958142131138,47575298963072,765124447990418, %U A226543 12305134306097753,197897152964385186,3182680323964197938,51185438892782012288,823189555932846017125 %N A226543 Number of tilings of a 9 X n rectangle using 1 X 1 squares and L-tiles. %C A226543 An L-tile is a 2 X 2 square with the upper right 1 X 1 subsquare removed and no rotations are allowed. %H A226543 Alois P. Heinz, <a href="/A226543/b226543.txt">Table of n, a(n) for n = 0..500</a> %H A226543 Alois P. Heinz, <a href="/A226543/a226543.txt">G.f. for A226543</a> %Y A226543 Column k=9 of A226444. %K A226543 nonn %O A226543 0,3 %A A226543 _Alois P. Heinz_, Jun 10 2013