Number of permutations p of [2n] such that the up-down signature of p has nonnegative partial sums with a maximal value of n.

A262127

Number of permutations p of [2n] such that the up-down signature of p has nonnegative partial sums with a maximal value of n.

Terms

    a(0) =1a(1) =1a(2) =3a(3) =57a(4) =778a(5) =47673a(6) =1477381a(7) =196352061a(8) =10896848134

External references