Atom-rooted polyenoids with n edges with symmetry class C_s.

Terms

a(0) =0a(1) =0a(2) =1a(3) =4a(4) =14a(5) =47a(6) =164a(7) =565a(8) =1982a(9) =6977a(10) =24850a(11) =89082a(12) =321855a(13) =1169853a(14) =4276923a(15) =15713799a(16) =57998270a(17) =214934984a(18) =799473752a(19) =2983682702a(20) =11169374372a(21) =41929478873a(22) =157807392886a(23) =595340271682