Number of n X n symmetric binary matrices with each 1 adjacent to no more than 3 horizontally or vertically neighboring 1's.
A191508
Number of n X n symmetric binary matrices with each 1 adjacent to no more than 3 horizontally or vertically neighboring 1's.
Terms
- a(0) =2a(1) =8a(2) =56a(3) =792a(4) =21984a(5) =1188160a(6) =125522112a(7) =25932064896
External references
- oeis: A191508