Number of n X n symmetric binary matrices with each 1 adjacent to no more than 4 horizontally, vertically or diagonally neighboring 1s.
A191603
Number of n X n symmetric binary matrices with each 1 adjacent to no more than 4 horizontally, vertically or diagonally neighboring 1s.
Terms
- a(0) =2a(1) =8a(2) =58a(3) =856a(4) =24368a(5) =1348666a(6) =145634012a(7) =30602076600
External references
- oeis: A191603