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

Terms

a(0) =22a(1) =158a(2) =684a(3) =2205a(4) =5852a(5) =13524a(6) =28176a(7) =54153a(8) =97570a(9) =166738a(10) =272636a(11) =429429a(12) =655032a(13) =971720a(14) =1406784a(15) =1993233a(16) =2770542a(17) =3785446a(18) =5092780a(19) =6756365a(20) =8849940a(21) =11458140a(22) =14677520a(23) =18617625a(24) =23402106a(25) =29169882a(26) =36076348a(27) =44294629a(28) =54016880