Half the number of symmetric n X n binary matrices with the center of gravity of the 1s at the center.
A139046
Half the number of symmetric n X n binary matrices with the center of gravity of the 1s at the center.
Terms
- a(0) =1a(1) =2a(2) =12a(3) =52a(4) =1992a(5) =43472a(6) =8084672a(7) =785972800a(8) =632010796352
External references
- oeis: A139046