Dimensions of graded algebra associated with meanders (subalgebra version).

Terms

a(0) =1a(1) =1a(2) =3a(3) =7a(4) =23a(5) =63a(6) =213a(7) =627a(8) =2149a(9) =6597a(10) =22787a(11) =71883a(12) =249523a(13) =802291a(14) =2794365a(15) =9111917a(16) =31814061a(17) =104862813a(18) =366796437a(19) =1219313185a(20) =4271041447a(21) =14295561451a(22) =50131159253a(23) =168742700865a(24) =592279599483