1220409

Appears in sequences

• Half the number of (n+1)X(n+1) symmetric 0..1 arrays with no 2X2 subblock summing to 2.at n=6A213690
• T(n,k)=Half the number of (n+1)X(n+1) symmetric 0..k arrays with no 2X2 subblock summing to 2k.at n=27A213697
• Half the number of 8X8 0..n symmetric arrays with no 2X2 subblock summing to 2n.at n=0A213703