Number of 3 X n 0..2 arrays with antidiagonals unimodal and rows and diagonals nondecreasing.

Terms

a(0) =27a(1) =157a(2) =476a(3) =1144a(4) =2403a(5) =4614a(6) =8291a(7) =14141a(8) =23109a(9) =36428a(10) =55674a(11) =82826a(12) =120331a(13) =171174a(14) =238953a(15) =327959a(16) =443261a(17) =590796a(18) =777464a(19) =1011228a(20) =1301219a(21) =1657846a(22) =2092911a(23) =2619729a(24) =3253253a(25) =4010204a(26) =4909206a(27) =5970926a(28) =7218219a(29) =8676278