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 A247774 #8 May 02 2022 10:02:49 %S A247774 1,1,5,56,461,3558,23966,178127,1362597,10194184,75684682,561877016, %T A247774 4192125848,31292310312,233221376211,1737652233817,12950437458383, %U A247774 96538803978663,719609376905074,5363567352622148,39977107204818978,297975192242698825,2221015587432193750 %N A247774 Number of tilings of a 5 X n rectangle using n pentominoes of any but the W shape. %H A247774 Alois P. Heinz, <a href="/A247774/b247774.txt">Table of n, a(n) for n = 0..500</a> %H A247774 Wikipedia, <a href="https://en.wikipedia.org/wiki/Pentomino">Pentomino</a> %Y A247774 Column k=0 of A247710. %Y A247774 Cf. A174249, A233427. %K A247774 nonn %O A247774 0,3 %A A247774 _Alois P. Heinz_, Sep 23 2014