1359352910domain: NAppears in sequencesT(n,k)=Number of (n+1)X(k+1) 0..3 arrays x(i,j) with row sums sum{x(i,j), j=1..k+1} nondecreasing, and column sums sum{i*x(i,j), i=1..n+1} nondecreasing.at n=18A232886