Search: id:A052700 Results 1-1 of 1 results found. %I A052700 %S A052700 0,1,4,36,432,6480,116640,2449440,58786560,1587237120,47617113600, %T A052700 1571364748800,56569130956800,2206196107315200,92660236507238400, %U A052700 4169710642825728000,200146110855634944000,10207451653637382144000 %N A052700 A simple regular expression in a labeled universe. %H A052700 INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 650 %F A052700 E.g.f.: x*(-1+x)/(-1+3*x) %F A052700 Recurrence: {a(1)=1, a(0)=0, a(2)=4, (-3*n-3)*a(n)+a(n+1)} %F A052700 2/9*3^n*n! %p A052700 spec := [S,{S=Prod(Z,Sequence(Prod(Sequence(Z),Union(Z,Z))))},labeled]: seq(combstruct[count](spec,size=n), n=0..20); %Y A052700 Sequence in context: A002894 A131765 A132864 this_sequence A167540 A136224 A009533 %Y A052700 Adjacent sequences: A052697 A052698 A052699 this_sequence A052701 A052702 A052703 %K A052700 easy,nonn %O A052700 0,3 %A A052700 encyclopedia(AT)pommard.inria.fr, Jan 25 2000 Search completed in 0.001 seconds