Riordan array (1,2+4x).

Terms

a(0) =1a(1) =0a(2) =2a(3) =0a(4) =4a(5) =4a(6) =0a(7) =0a(8) =16a(9) =8a(10) =0a(11) =0a(12) =16a(13) =48a(14) =16a(15) =0a(16) =0a(17) =0a(18) =96a(19) =128a(20) =32a(21) =0a(22) =0a(23) =0a(24) =64a(25) =384a(26) =320a(27) =64a(28) =0a(29) =0