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 A052870 #27 Jan 13 2025 08:03:32
%S A052870 1,1,2,6,15,44,128,386,1179,3679,11601,37030,119262,387325,1266647,
%T A052870 4168264,13791565,45856091,153134306,513403575,1727395042,5830866601,
%U A052870 19740613869,67014421326,228066659185,777961702283,2659398743509,9109015516017,31258117755635
%N A052870 First differences of A052829.
%C A052870 Old name was: A simple grammar.
%H A052870 INRIA Algorithms Project, <a href="http://ecs.inria.fr/services/structure?nbr=841">Encyclopedia of Combinatorial Structures 841</a>
%F A052870 From _Seiichi Manyama_, Jun 07 2023: (Start)
%F A052870 Conjectures: G.f. satisfies A(x) = exp( Sum_{k>=1} (-1)^(k+1) * A(x^k) * x^k/(k * (1 - x^k)) ).
%F A052870 A(x) = Sum_{k>=0} a(k) * x^k = Product_{j>=1} Product_{k>=0} (1+x^(j+k))^a(k). (End)
%p A052870 spec := [S,{C=Sequence(Z,1 <= card),S=PowerSet(B),B=Prod(C,S)},unlabeled]: seq(combstruct[count](spec,size=n), n=0..20);
%Y A052870 Cf. A052829, A052855.
%K A052870 easy,nonn
%O A052870 0,3
%A A052870 encyclopedia(AT)pommard.inria.fr, Jan 25 2000
%E A052870 More terms from _Alois P. Heinz_, Mar 16 2016