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 A232698 #22 Feb 07 2017 17:11:07 %S A232698 1,1,25,997,40899,800290,22483347,657253434,19077209438,517312744806, %T A232698 14571957312254,412240433359025,11632857444709188,326275845576101452, %U A232698 9187549952207915190,258821654387452112268,7288072624408347082481,205113474464891986564786 %N A232698 Number of tilings of an 8 X n rectangle with 2n tetrominoes of any shape. %H A232698 Alois P. Heinz, <a href="/A232698/b232698.txt">Table of n, a(n) for n = 0..300</a> %H A232698 S. Butler, J. Ekstrand, S. Osborne, <a href="/A230031/a230031.pdf">TETRIS Tiling</a>, AMS Spring Central Sectional, Iowa State University, April 27-28 2013 %H A232698 Wikipedia, <a href="https://en.wikipedia.org/wiki/Tetromino">Tetromino</a> %Y A232698 Cf. A174248, A232684, A232722. %Y A232698 Column k=8 of A230031. %K A232698 nonn %O A232698 0,3 %A A232698 _Alois P. Heinz_, Nov 27 2013