Number of Dyck bridges with resets to zero from (0,0) to (n,0).

Terms

a(0) =1a(1) =0a(2) =2a(3) =2a(4) =8a(5) =14a(6) =40a(7) =84a(8) =216a(9) =486a(10) =1200a(11) =2780a(12) =6744a(13) =15836a(14) =38096a(15) =90056a(16) =215728a(17) =511750a(18) =1223136a(19) =2907052a(20) =6939544a(21) =16511028a(22) =39386384a(23) =93768696a(24) =223589648a(25) =532502748a(26) =1269433376a(27) =3023953560a(28) =7207744496a(29) =17172061944