Number of ways to lace a shoe that has n pairs of eyelets such that each eyelet has at least one direct connection to the opposite side.

A078702

Number of ways to lace a shoe that has n pairs of eyelets such that each eyelet has at least one direct connection to the opposite side.

Terms

    a(0) =1a(1) =2a(2) =13a(3) =213a(4) =7584a(5) =454380a(6) =39665160a(7) =4775586480a(8) =756765576000

External references