Riordan array (1,2-x).

Terms

a(0) =1a(1) =0a(2) =2a(3) =0a(4) =-1a(5) =4a(6) =0a(7) =0a(8) =-4a(9) =8a(10) =0a(11) =0a(12) =1a(13) =-12a(14) =16a(15) =0a(16) =0a(17) =0a(18) =6a(19) =-32a(20) =32a(21) =0a(22) =0a(23) =0a(24) =-1a(25) =24a(26) =-80a(27) =64a(28) =0a(29) =0