Half the number of (n+1) X (n+1) symmetric 0..4 arrays with no 2 X 2 subblock summing to 8.
A213693
Half the number of (n+1) X (n+1) symmetric 0..4 arrays with no 2 X 2 subblock summing to 8.
Terms
- a(0) =56a(1) =5470a(2) =2322599a(3) =4286833981
External references
- oeis: A213693