48904686848domain: NAppears in sequencesNumber of ordered pairs (p,q) of permutations of [n] with equal up-down signatures and p(1)=q(1)=2.at n=9A262479Number of ordered pairs (p,q) of permutations of [n] with equal up-down signatures and p(1)=q(1)=10.at n=1A321066