Generalized Catalan numbers for triangle A119335.

Terms

a(0) =1a(1) =0a(2) =0a(3) =1a(4) =6a(5) =20a(6) =51a(7) =126a(8) =392a(9) =1513a(10) =5877a(11) =21054a(12) =71270a(13) =242463a(14) =863590a(15) =3193737a(16) =11889414a(17) =43783908a(18) =159998493a(19) =586908936a(20) =2175907284a(21) =8138471667a(22) =30541703733a(23) =114620380032a(24) =430344635913