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 A270066 #6 Feb 06 2017 12:32:29 %S A270066 1,6,438,23509,1238818,65410388,3473827027,184140417890,9756894398324, %T A270066 517174361985073,27412100990502042,1452889626133073024, %U A270066 77006768282516987969,4081555197498259422846,216332403430110823588762,11466150014825389043509015 %N A270066 Number of tilings of a 6 X n rectangle using monominoes and trominoes of any shape. %H A270066 Alois P. Heinz, <a href="/A270066/b270066.txt">Table of n, a(n) for n = 0..580</a> %H A270066 Wikipedia, <a href="https://en.wikipedia.org/wiki/Tromino">Tromino</a> %Y A270066 Column k=6 of A270061. %K A270066 nonn %O A270066 0,2 %A A270066 _Alois P. Heinz_, Mar 09 2016