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 A220059 #4 Dec 03 2012 17:19:03 %S A220059 1,1,4895,358397,103628653,16939662301,3448441154503,643234164533111, %T A220059 124179182077944123,23649239068131551559,4528155459015015278497, %U A220059 865169296748334990311763,165442366105217743521821785,31626233120646483498726015897,6046521630766477909485058575551 %N A220059 Number of tilings of a 9 X n rectangle using right trominoes and 1 X 1 tiles. %H A220059 Alois P. Heinz, <a href="/A220059/b220059.txt">Table of n, a(n) for n = 0..150</a> %Y A220059 Column k=9 of A220054. %K A220059 nonn %O A220059 0,3 %A A220059 _Alois P. Heinz_, Dec 03 2012