Number of ways to lace a shoe that has n pairs of eyelets such that the lace does not cross itself between the eyelet rows.

A079410

Number of ways to lace a shoe that has n pairs of eyelets such that the lace does not cross itself between the eyelet rows.

Terms

    a(0) =2a(1) =7a(2) =54a(3) =308a(4) =2890a(5) =25764

External references