Number of permutations of {0,1,...,2n+2} with first element n whose sequence of ascents and descents forms a Dyck path.

A316730

Number of permutations of {0,1,...,2n+2} with first element n whose sequence of ascents and descents forms a Dyck path.

Terms

    a(0) =1a(1) =7a(2) =121a(3) =4411a(4) =283073a(5) =28318137a(6) =4076415425a(7) =798519164779

External references