Number of n X n symmetric binary matrices with every 1 adjacent horizontally (and vertically) to some other 1.
A140363
Number of n X n symmetric binary matrices with every 1 adjacent horizontally (and vertically) to some other 1.
Terms
- a(0) =1a(1) =2a(2) =8a(3) =40a(4) =310a(5) =4155a(6) =89670a(7) =3070348a(8) =168002166a(9) =14759284768
External references
- oeis: A140363