Number of n-steps skew Dyck paths that come back to the x-axis.

Terms

a(0) =1a(1) =0a(2) =1a(3) =1a(4) =4a(5) =5a(6) =17a(7) =25a(8) =76a(9) =125a(10) =353a(11) =625a(12) =1681a(13) =3130a(14) =8138a(15) =15708a(16) =39848a(17) =78995a(18) =196718a(19) =398013a(20) =977055a(21) =2008700a(22) =4875392a(23) =10152167a(24) =24416134a(25) =51374143a(26) =122631570a(27) =260255863a(28) =617373878a(29) =1319669672