T(n,k)=Number of nXk 0..3 arrays with antidiagonals unimodal.

Terms

a(0) =4a(1) =16a(2) =16a(3) =64a(4) =256a(5) =64a(6) =256a(7) =4096a(8) =4096a(9) =256a(10) =1024a(11) =65536a(12) =204800a(13) =65536a(14) =1024a(15) =4096a(16) =1048576a(17) =10240000a(18) =10240000a(19) =1048576a(20) =4096a(21) =16384a(22) =16777216a(23) =512000000a(24) =1331200000a(25) =512000000a(26) =16777216a(27) =16384a(28) =65536a(29) =268435456