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 A219992 #4 Dec 02 2012 18:33:46 %S A219992 1,0,569,26676,3962734,342302244,37873593799,3704964324320, %T A219992 385840008972355,38896105985522272,3988620629294917699, %U A219992 405324462894583579568,41388678831664101508625,4215380264404938792346540,429927047644440948315400804,43815601312259648266416292348 %N A219992 Number of tilings of a 9 X n rectangle using dominoes and right trominoes. %H A219992 Alois P. Heinz, <a href="/A219992/b219992.txt">Table of n, a(n) for n = 0..200</a> %Y A219992 Column k=9 of A219987. %K A219992 nonn %O A219992 0,3 %A A219992 _Alois P. Heinz_, Dec 02 2012