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 A247771 #8 May 02 2022 10:01:59 %S A247771 1,1,5,50,437,3270,21720,160593,1209537,8999307,66054288,485082083, %T A247771 3583263174,26469863097,195317239597,1440271919247,10624063817149, %U A247771 78389991175482,578363501074881,4266856868607953,31478045125433448,232231064765922254,1713315860292710073 %N A247771 Number of tilings of a 5 X n rectangle using n pentominoes of any but the T shape. %H A247771 Alois P. Heinz, <a href="/A247771/b247771.txt">Table of n, a(n) for n = 0..500</a> %H A247771 Wikipedia, <a href="https://en.wikipedia.org/wiki/Pentomino">Pentomino</a> %Y A247771 Column k=0 of A247707. %Y A247771 Cf. A174249, A233427. %K A247771 nonn %O A247771 0,3 %A A247771 _Alois P. Heinz_, Sep 23 2014