Generalized Catalan numbers C(5; n).

Terms

a(0) =1a(1) =1a(2) =6a(3) =61a(4) =766a(5) =10746a(6) =161376a(7) =2537781a(8) =41260086a(9) =687927166a(10) =11698135396a(11) =202104763026