T(n,k)=Number of (n+1)X(k+1) 0..3 arrays with 2X2 subblock sums lexicographically nondecreasing columnwise and rowwise.
A235261
T(n,k)=Number of (n+1)X(k+1) 0..3 arrays with 2X2 subblock sums lexicographically nondecreasing columnwise and rowwise.
Terms
- a(0) =256a(1) =2400a(2) =2400a(3) =22500a(4) =75744a(5) =22500a(6) =162000a(7) =2691067a(8) =2691067a(9) =162000a(10) =1166400a(11) =64470056a(12) =417967682a(13) =64470056a(14) =1166400a(15) =7157160a(16) =1538378437a(17) =41170730836a(18) =41170730836a(19) =1538378437a(20) =7157160a(21) =43917129a(22) =27988093692
External references
- oeis: A235261