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 A254607 #9 Dec 24 2019 08:32:33 %S A254607 1,64,9866,2078716,486248000,117656540512,28778500622048, %T A254607 7063448084710944,1735575086258267968,426602245391808219456, %U A254607 104870171042459607741312,25780811901305515395438592,6337913024506813766449064064,1558108119479642808250383381248,383044676600298851289615284801792 %N A254607 Number of tilings of a 7 X n rectangle using polyominoes of shape I. %C A254607 A polyomino of shape I is a rectangle of width 1. %H A254607 Andrew Howroyd, <a href="/A254607/b254607.txt">Table of n, a(n) for n = 0..200</a> %H A254607 Wikipedia, <a href="https://en.wikipedia.org/wiki/Polyomino">Polyomino</a> %Y A254607 Column k=7 of A254414. %K A254607 nonn %O A254607 0,2 %A A254607 _Alois P. Heinz_, Feb 02 2015 %E A254607 Terms a(11) and beyond from _Andrew Howroyd_, Dec 23 2019