a(n) is the hafnian of a symmetric Toeplitz matrix M(2n) whose first row consists of a single zero followed by successive positive integers repeated (A004526).
A338456
a(n) is the hafnian of a symmetric Toeplitz matrix M(2n) whose first row consists of a single zero followed by successive positive integers repeated (A004526).
Terms
- a(0) =1a(1) =1a(2) =4a(3) =45a(4) =968a(5) =34265a(6) =1799748a(7) =131572357a(8) =12770710096
External references
- oeis: A338456