The hafnian of a symmetric Toeplitz matrix of order 2*n, n>=2 with the first row (0,2,1,...,1,2); a(0)=1, a(1)=2.

A336400

The hafnian of a symmetric Toeplitz matrix of order 2*n, n>=2 with the first row (0,2,1,...,1,2); a(0)=1, a(1)=2.

Terms

    a(0) =1a(1) =2a(2) =9a(3) =44a(4) =303a(5) =2697a(6) =29438a(7) =380529a(8) =5683359a(9) =96290588a(10) =1824544857a(11) =38229811083a(12) =877643031554

External references