T(n,k)=Number of (n+1)X(k+1) 0..3 arrays with nondecreasing min(x(i,j),x(i,j-1)) in the i direction and nondecreasing min(x(i,j),x(i-1,j)) in the j direction.

A250519

T(n,k)=Number of (n+1)X(k+1) 0..3 arrays with nondecreasing min(x(i,j),x(i,j-1)) in the i direction and nondecreasing min(x(i,j),x(i-1,j)) in the j direction.

Terms

    a(0) =120a(1) =889a(2) =889a(3) =5996a(4) =14660a(5) =5996a(6) =39187a(7) =205022a(8) =205022a(9) =39187a(10) =248942a(11) =2817780a(12) =5941982a(13) =2817780a(14) =248942a(15) =1555689a(16) =36999777a(17) =166583429a(18) =166583429a(19) =36999777a(20) =1555689a(21) =9605300a(22) =480626844a(23) =4464289109a(24) =9680713976a(25) =4464289109a(26) =480626844

External references