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 A052629 #19 May 19 2023 04:16:41
%S A052629 1,4,34,438,7536,162120,4185360,126060480,4339278720,168038478720,
%T A052629 7230318681600,342214829510400,17669683572710400,988372892015308800,
%U A052629 59538455210371737600,3842709218808235776000,264549049753191211008000
%N A052629 Expansion of e.g.f. (1-x)/(1-5x+3x^2).
%H A052629 INRIA Algorithms Project, <a href="http://ecs.inria.fr/services/structure?nbr=575">Encyclopedia of Combinatorial Structures 575</a> [broken link].
%F A052629 E.g.f.: -(-1+x)/(1-5*x+3*x^2).
%F A052629 Recurrence: a(0)=1, a(1)=4, (3*n^2+9*n+6)*a(n) +(-10-5*n)*a(n+1) +a(n+2)=0.
%F A052629 Sum(-1/13*(-3+_alpha)*_alpha^(-1-n), _alpha=RootOf(1-5*_Z+3*_Z^2))*n!
%F A052629 a(n) = n!*A018902(n). - _R. J. Mathar_, Jun 03 2022
%p A052629 spec := [S,{S=Sequence(Union(Z,Z,Z,Prod(Z,Sequence(Z))))},labeled]: seq(combstruct[count](spec,size=n), n=0..20);
%Y A052629 Cf. A018902.
%K A052629 easy,nonn
%O A052629 0,2
%A A052629 encyclopedia(AT)pommard.inria.fr, Jan 25 2000