Half the number of n X n symmetric binary matrices with each 1 adjacent to an even number of other 1's.
A140963
Half the number of n X n symmetric binary matrices with each 1 adjacent to an even number of other 1's.
Terms
- a(0) =1a(1) =3a(2) =14a(3) =99a(4) =1082a(5) =17997a(6) =460186a(7) =17967189a(8) =1075650798a(9) =98475760770
External references
- oeis: A140963