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 A289479 #10 Jul 14 2017 08:49:28
%S A289479 1,1,131071,53249182309,24707711028329725,10683679703096752747668,
%T A289479 4147304882800594101766257490,1455763914060254648633279812633997,
%U A289479 470172045819740629127626302976354304026,142143740345412121643458345045577780672138977
%N A289479 Number of Dyck paths of semilength 9*n and height n.
%H A289479 Alois P. Heinz, <a href="/A289479/b289479.txt">Table of n, a(n) for n = 0..186</a>
%F A289479 a(n) ~ 3^(36*n + 1) / (2^(16*n + 2)* 5^(10*n + 7/2) * sqrt(Pi*n)). - _Vaclav Kotesovec_, Jul 14 2017
%p A289479 b:= proc(x, y, k) option remember;
%p A289479 `if`(x=0, 1, `if`(y>0, b(x-1, y-1, k), 0)+
%p A289479 `if`(y < min(x-1, k), b(x-1, y+1, k), 0))
%p A289479 end:
%p A289479 a:= n-> `if`(n=0, 1, b(18*n, 0, n)-b(18*n, 0, n-1)):
%p A289479 seq(a(n), n=0..20);
%t A289479 b[x_, y_, k_]:=b[x, y, k]=If[x==0, 1, If[y>0, b[x - 1, y - 1, k], 0] + If[y<Min[x - 1, k], b[x - 1, y + 1, k], 0]]; a[n_]:=a[n]=If[n==0, 1, b[18n, 0, n] - b[18n, 0, n - 1]]; Table[a[n], {n, 0, 20}] (* _Indranil Ghosh_, Jul 07 2017, after Maple code *)
%Y A289479 Column k=9 of A289481.
%K A289479 nonn
%O A289479 0,3
%A A289479 _Alois P. Heinz_, Jul 06 2017