Number of ordered pairs (p,q) of permutations of [n] with equal up-down signatures and p(1)=q(1)=7.

A321063

Number of ordered pairs (p,q) of permutations of [n] with equal up-down signatures and p(1)=q(1)=7.

Terms

    a(0) =24176a(1) =533544a(2) =16860608a(3) =707767328a(4) =37727416576

External references