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 A270065 #9 Feb 06 2017 12:31:59 %S A270065 1,4,140,3710,96176,2501946,65410388,1707101599,44538604036, %T A270065 1162378878394,30334909910156,791636651386694,20659194865202206, %U A270065 539139829390310029,14069828639020139191,367177676400256677129,9582168262012437486944,250064069442551102774366 %N A270065 Number of tilings of a 5 X n rectangle using monominoes and trominoes of any shape. %H A270065 Alois P. Heinz, <a href="/A270065/b270065.txt">Table of n, a(n) for n = 0..700</a> %H A270065 Vaclav Kotesovec, <a href="/A270065/a270065.txt">Recurrence (of order 135) and g.f.</a> %H A270065 Wikipedia, <a href="https://en.wikipedia.org/wiki/Tromino">Tromino</a> %Y A270065 Column k=5 of A270061. %K A270065 nonn %O A270065 0,2 %A A270065 _Alois P. Heinz_, Mar 09 2016