Number of 3 X n 0..1 arrays with diagonals and rows unimodal and antidiagonals nondecreasing.

Terms

a(0) =8a(1) =36a(2) =89a(3) =187a(4) =373a(5) =702a(6) =1252a(7) =2130a(8) =3479a(9) =5486a(10) =8391a(11) =12497a(12) =18181a(13) =25906a(14) =36234a(15) =49840a(16) =67527a(17) =90242a(18) =119093a(19) =155367a(20) =200549a(21) =256342a(22) =324688a(23) =407790a(24) =508135a(25) =628518a(26) =772067a(27) =942269a(28) =1142997a(29) =1378538