3897880domain: NAppears in sequences1/4 the number of (n+1) X 2 0..3 arrays with every 2 X 2 subblock having distinct edge sums.at n=7A209729T(n,k)=1/4 the number of (n+1)X(k+1) 0..3 arrays with every 2X2 subblock having distinct edge sums.at n=28A209736