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 A052768 #19 Apr 05 2025 01:20:28
%S A052768 0,0,0,0,0,120,360,840,1680,3024,5040,7920,11880,17160,24024,32760,
%T A052768 43680,57120,73440,93024,116280,143640,175560,212520,255024,303600,
%U A052768 358800,421200,491400,570024,657720,755160,863040,982080,1113024
%N A052768 a(n) = n*(n-1)*(n-2)*(n-3) for n>=5.
%C A052768 Old name was: A simple grammar.
%H A052768 INRIA Algorithms Project, <a href="http://ecs.inria.fr/services/structure?nbr=725">Encyclopedia of Combinatorial Structures 725</a>
%H A052768 <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (5,-10,10,-5,1).
%F A052768 a(n)=0, n <= 4; a(n) = n*(n-1)*(n-2)*(n-3), n >= 5.
%F A052768 G.f.: 24*x^5*(5-10*x+10*x^2-5*x^3+x^4)/(1-x)^5. - _Colin Barker_, Jun 25 2012
%p A052768 spec := [S,{B=Set(Z,1 <= card),S=Prod(Z,Z,Z,Z,B)},labeled]: seq(combstruct[count](spec,size=n), n=0..20);
%Y A052768 Essentially the same as A052762.
%K A052768 easy,nonn
%O A052768 0,6
%A A052768 encyclopedia(AT)pommard.inria.fr, Jan 25 2000
%E A052768 More terms and corrected formula from Larry Reeves (larryr(AT)acm.org), Jan 23 2001