The number of permutations of {1,2,...,2n} with n ascents.

A180056

The number of permutations of {1,2,...,2n} with n ascents.

Terms

    a(0) =1a(1) =1a(2) =11a(3) =302a(4) =15619a(5) =1310354a(6) =162512286a(7) =27971176092

External references