Number of binary n X n matrices symmetric about both diagonals with rows, considered as binary numbers, in nondecreasing order.
A140974
Number of binary n X n matrices symmetric about both diagonals with rows, considered as binary numbers, in nondecreasing order.
Terms
- a(0) =1a(1) =2a(2) =3a(3) =4a(4) =8a(5) =16a(6) =43a(7) =136a(8) =513a(9) =2662a(10) =15276a(11) =134366a(12) =1233504a(13) =18634052a(14) =281749759a(15) =7363023774a(16) =187712397424
External references
- oeis: A140974