Table read by antidiagonals: T(n,k) = number of distinct n X k toroidal 0..3 arrays.

Terms

a(0) =4a(1) =10a(2) =10a(3) =24a(4) =76a(5) =24a(6) =70a(7) =700a(8) =700a(9) =70a(10) =208a(11) =8296a(12) =29184a(13) =8296a(14) =208a(15) =700a(16) =104968a(17) =1398500a(18) =1398500a(19) =104968a(20) =700a(21) =2344a(22) =1399176a(23) =71582944a(24) =268447936a(25) =71582944a(26) =1399176a(27) =2344a(28) =8230a(29) =19175140