T(n,k)=Number of nXk 0..2 arrays with antidiagonals unimodal.

Terms

a(0) =3a(1) =9a(2) =9a(3) =27a(4) =81a(5) =27a(6) =81a(7) =729a(8) =729a(9) =81a(10) =243a(11) =6561a(12) =16038a(13) =6561a(14) =243a(15) =729a(16) =59049a(17) =352836a(18) =352836a(19) =59049a(20) =729a(21) =2187a(22) =531441a(23) =7762392a(24) =16230456a(25) =7762392a(26) =531441a(27) =2187a(28) =6561a(29) =4782969