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 A007761 #22 Mar 04 2020 16:28:23
%S A007761 1,54,6381,1176900,295843509,94263721650,36391089828249,
%T A007761 16506884910849480,8603605199199386025,5066519768097762780270,
%U A007761 3326644994941284848273925,2409605195467508091244871820
%N A007761 (n+1) * a(n+1) - 2 (68*n^2+68*n+27) * a(n) + 6 * n * (772*n^2+35) * a(n-1) - 2 * (2*n-1)^2 * (68*n^2-68*n+27) * a(n-2) + (2*n-1)^2 * (n-1) * (2*n-3)^2 * a(n-3) = 0.
%C A007761 Is this always integral?
%H A007761 G. C. Greubel, <a href="/A007761/b007761.txt">Table of n, a(n) for n = 0..250</a>
%p A007761 a[0]:=1: a[1]:=54: a[2]:=6381: a[3]:=1176900: for n from 3 to 11 do a[n+1]:=(2*(68*n^2+68*n+27)*a[n]-6*n*(772*n^2+35)*a[n-1]+2*(2*n-1)^2* (68*n^2-68*n+27)*a[n-2]-(2*n-1)^2*(n-1)*(2*n-3)^2*a[n-3])/(n+1) od: seq(a[n],n=0..12); # _Emeric Deutsch_, Jul 20 2005
%t A007761 a[0]:=1; a[1]:=54; a[2]:=6381; a[3]:=1176900; a[n_]:= a[n]= (2*(68*(n-1)^2 + 68*(n-1) +27)*a[n-1] -6*(n-1)*(772*(n-1)^2 +35)*a[n-2] +2*(2*n-3)^2*(68*(n- 1)^2 -68*(n-1) +27)*a[n-3] -(2*n-3)^2*(n-2)*(2*n-5)^2*a[n-4])/n; Table[a[n], {n, 0, 12}] (* _G. C. Greubel_, Mar 04 2020 *)
%K A007761 nonn
%O A007761 0,2
%A A007761 _Bruno Haible_
%E A007761 More terms from _Emeric Deutsch_, Jul 20 2005