T(n,k)=Number of (n+1)X(k+1) 0..3 arrays with the sums of 2X2 subblocks nondecreasing rightwards and downwards.

A204309

T(n,k)=Number of (n+1)X(k+1) 0..3 arrays with the sums of 2X2 subblocks nondecreasing rightwards and downwards.

Terms

    a(0) =256a(1) =2400a(2) =2400a(3) =22500a(4) =51680a(5) =22500a(6) =162000a(7) =1077978a(8) =1077978a(9) =162000a(10) =1166400a(11) =15057392a(12) =47834122a(13) =15057392a(14) =1166400a(15) =7157160a(16) =209106648a(17) =1271789125a(18) =1271789125a(19) =209106648a(20) =7157160a(21) =43917129a(22) =2204400210a(23) =32895567670

External references