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 A247218 #12 Feb 06 2017 18:21:16 %S A247218 1,1,1,1,1,34,95,190,325,506,3324,10353,25607,55346,108756,389216, %T A247218 1208901,3281686,8006108,17950204,51430928,150609259,419540401, %U A247218 1090827453,2651884943,7077981621,19691707908,54499735145,145671654672,371632691473,976543067070 %N A247218 Number of tilings of a 15 X n rectangle using 3n pentominoes of shape I. %H A247218 Alois P. Heinz, <a href="/A247218/b247218.txt">Table of n, a(n) for n = 0..1000</a> %H A247218 Wikipedia, <a href="https://en.wikipedia.org/wiki/Pentomino">Pentomino</a> %Y A247218 Cf. A174249, A233427, A003520, A247117. %Y A247218 Column k=5 of A251072. %K A247218 nonn %O A247218 0,6 %A A247218 _Alois P. Heinz_, Nov 26 2014