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 A174810 #14 Jan 30 2014 05:24:44
%S A174810 1,1,4,17,81,410,2169,11847,66306,378297,2192011,12864668,76313865,
%T A174810 456837181,2756271064,16743326577,102319639173,628599899558,
%U A174810 3880049052441,24051163355499,149654739889478,934426798835377
%N A174810 A transform of the little Schroeder numbers A001003.
%C A174810 Hankel transform is A174811.
%H A174810 Fung Lam, <a href="/A174810/b174810.txt">Table of n, a(n) for n = 0..1000</a>
%F A174810 G.f.: (1+x+x^2-sqrt(1-6x-5x^2+2x^3+x^4))/(4x(1+x));
%F A174810 G.f.: 1/(1-x(1+x)/(1-2x(1+x)/(1-x(1+x)/(1-2x(1+x)/(1-... (continued fraction);
%F A174810 a(n)=sum{k=0..n, C(k,n-k)*A001003(k)}.
%F A174810 Recurrence: (n+1)*a(n) = (5-n)*a(n-5) - 3*(n-4)*a(n-4) + 3*(n-1)*a(n-3) + (11*n-13)*a(n-2) + (5*n-4)*a(n-1). - _Fung Lam_, Jan 30 2014
%t A174810 CoefficientList[Series[(1+x+x^2-Sqrt[1-6*x-5*x^2+2*x^3+x^4])/(4*x*(1+x)), {x, 0, 20}], x] (* _Vaclav Kotesovec_, Jan 30 2014 *)
%o A174810 (PARI) x='x+O('x^66); Vec((1+x+x^2-sqrt(1-6*x-5*x^2+2*x^3+x^4))/(4*x*(1+x))) \\ _Joerg Arndt_, Jan 30 2014
%K A174810 easy,nonn
%O A174810 0,3
%A A174810 _Paul Barry_, Mar 29 2010