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 A110580 #10 Sep 01 2017 03:04:20
%S A110580 1,5,16,45,132,449,1816,8460,43717,244869,1469094,9375888,63337464,
%T A110580 451011317,3372983491,26409145110,215868629023,1837579724641,
%U A110580 16254473067368,149114870667176,1416212525570460,13902957827280263
%N A110580 {a(4,n)}, where a(m,n) is as defined in sequence A110576.
%H A110580 G. C. Greubel, <a href="/A110580/b110580.txt">Table of n, a(n) for n = 0..570</a>
%t A110580 a[0, 0] := 1; a[0, 1] := 1; a[0, n_] := a[0, n] = Sum[Binomial[2*n - k - 3, n - 2]*a[0, k], {k, 0, n - 1}]; a[1, 0] := 1; a[1, n_] := a[1, n] = a[1, n - 1] + a[0, n]; a[2, 0] := 1; a[2, n_] := a[2, n] = a[2, n - 1] + a[1, n]; a[3, 0] := 1; a[3, n_] := a[3, n] = a[3, n - 1] + a[2, n]; a[4, 0] := 1; a[4, n_] := a[4, n] = a[4, n - 1] + a[3, n]; Table[a[4, n], {n, 0, 50}] (* _G. C. Greubel_, Sep 01 2017 *)
%Y A110580 Cf. A110576, A110577, A110578, A110579.
%K A110580 easy,nonn
%O A110580 0,2
%A A110580 _Leroy Quet_, Jul 28 2005
%E A110580 More terms from _Ryan Propper_, Sep 25 2005