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 A068180 #24 Jan 09 2021 11:03:58
%S A068180 1,25,625,11095,164125,2201575,28021525,346791295,4228592125,
%T A068180 51161968375,616523997925,7414045240495,89064205082125,
%U A068180 1069348964379175,12835676881182325,154049132081273695
%N A068180 (Product_{i=1..4} (x+i)) / (Product_{i=1..4} (x-i)) = Sum_{n>=1} a(n)/A067419(n)*x^n.
%H A068180 Vincenzo Librandi, <a href="/A068180/b068180.txt">Table of n, a(n) for n = 1..900</a>
%H A068180 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (25,-210,720,-864).
%F A068180 Lim_{n->infinity} a(n)/A067419(n) = 20.
%F A068180 For n > 1, a(n) = (5/6)*12^n - (15/2)*6^n + (35/2)*4^n - (35/3)*3^n. - _Ralf Stephan_, May 08 2004
%F A068180 G.f.: x*(864*x^4 + 210*x^2 + 1) / ((3*x-1)*(4*x-1)*(6*x-1)*(12*x-1)). - _Colin Barker_, Jun 17 2013
%t A068180 LinearRecurrence[{25,-210,720,-864},{1,25,625,11095,164125},30] (* _Harvey P. Dale_, Oct 28 2015 *)
%Y A068180 Cf. A067419.
%K A068180 easy,nonn
%O A068180 1,2
%A A068180 _Benoit Cloitre_, Mar 12 2002