5273355420domain: NAppears in sequences1/6 the number of (n+2)X3 0..2 arrays with each 3X3 subblock containing two of one value, three of another, and four of the last.at n=6A184404T(n,k)=1/6 the number of (n+2)X(k+2) 0..2 arrays with each 3X3 subblock containing two of one value, three of another, and four of the last.at n=21A184407