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 A251074 #7 Feb 06 2017 18:20:46 %S A251074 1,1,1,1,26,75,154,269,1732,5764,15131,34345,135950,462186,1356284, %T A251074 3539433,11681091,38519022,118366429,334591568,1037603086,3309045401, %U A251074 10296063522,30414763937,92735958046,289374852696,899439481823,2716896548850,8270384213984 %N A251074 Number of tilings of a 12 X n rectangle using 3n tetrominoes of shape I. %H A251074 Alois P. Heinz, <a href="/A251074/b251074.txt">Table of n, a(n) for n = 0..1000</a> %H A251074 Wikipedia, <a href="https://en.wikipedia.org/wiki/Tetromino">Tetromino</a> %Y A251074 Column k=4 of A251072. %Y A251074 Cf. A236582. %K A251074 nonn %O A251074 0,5 %A A251074 _Alois P. Heinz_, Nov 29 2014