a(n) is the hafnian of a symmetric Toeplitz matrix M(2*n) whose first row consists of 2*n, 2*n-1, ..., 1.

A356482

a(n) is the hafnian of a symmetric Toeplitz matrix M(2*n) whose first row consists of 2*n, 2*n-1, ..., 1.

Terms

    a(0) =1a(1) =1a(2) =16a(3) =714a(4) =62528a(5) =9056720a(6) =1960138560a(7) =592615689904

External references