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 A247113 #13 Feb 07 2017 10:26:49 %S A247113 1,179399,517312744806,2045387873615550415,8355513115448789147187273, %T A247113 34243737232278596352691552132065, %U A247113 140387532129057613906130882433658669281,575558645377903777492614229836093710424726422,2359673678366714374809214450385908918997931183691473 %N A247113 Number of tilings of a 9 X 4n rectangle with 9n tetrominoes of any shape. %H A247113 Alois P. Heinz, <a href="/A247113/b247113.txt">Table of n, a(n) for n = 0..40</a> %H A247113 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 A247113 R. S. Harris, <a href="http://www.bumblebeagle.org/polyominoes/tilingcounting">Counting Polyomino Tilings</a> %H A247113 Wikipedia, <a href="https://en.wikipedia.org/wiki/Tetris">Tetris</a> %H A247113 Wikipedia, <a href="https://en.wikipedia.org/wiki/Tetromino">Tetromino</a> %Y A247113 Quadrisection of column k=9 of A230031. %K A247113 nonn %O A247113 0,2 %A A247113 _Alois P. Heinz_, Nov 19 2014