Number of ways to group the first 2*n natural numbers into n pairs (xi,yi) with yi>xi, and such that the 2*n numbers xi+yi and xi-yi are all different.

A272363

Number of ways to group the first 2*n natural numbers into n pairs (xi,yi) with yi>xi, and such that the 2*n numbers xi+yi and xi-yi are all different.

Terms

    a(0) =1a(1) =1a(2) =0a(3) =2a(4) =12a(5) =64a(6) =220a(7) =1886a(8) =16346a(9) =142420a(10) =1302106a(11) =14467384a(12) =177079358

External references