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 A247776 #8 May 02 2022 10:03:19 %S A247776 1,1,5,44,321,2404,14692,98831,684729,4642752,31650422,213894450, %T A247776 1451388234,9868405649,66968132029,454745989239,3086695784357, %U A247776 20954497956277,142275120134328,965860855067492,6557295186301572,44517125016379779,302224231486908372 %N A247776 Number of tilings of a 5 X n rectangle using n pentominoes of any but the Y shape. %H A247776 Alois P. Heinz, <a href="/A247776/b247776.txt">Table of n, a(n) for n = 0..500</a> %H A247776 Wikipedia, <a href="https://en.wikipedia.org/wiki/Pentomino">Pentomino</a> %Y A247776 Column k=0 of A247712. %Y A247776 Cf. A174249, A233427. %K A247776 nonn %O A247776 0,3 %A A247776 _Alois P. Heinz_, Sep 23 2014