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 A247119 #12 Feb 07 2017 10:41:07 %S A247119 1,0,4,0,52,194,808,2858,13998,66154,378268,1550370,7987672,37394810, %T A247119 190191026,958595712,4634180280,23153016922,114436235324,570764742248, %U A247119 2855728422214,14134719577328,70532689287114,350910293711340,1748728132235334,8722708834873854 %N A247119 Number of tilings of a 10 X n rectangle using 2n pentominoes of shape P. %H A247119 Alois P. Heinz, <a href="/A247119/b247119.txt">Table of n, a(n) for n = 0..800</a> %H A247119 Wikipedia, <a href="https://en.wikipedia.org/wiki/Pentomino">Pentomino</a> %Y A247119 Cf. A174249, A233427. %K A247119 nonn %O A247119 0,3 %A A247119 _Alois P. Heinz_, Nov 19 2014