A transform of the Motzkin numbers.

Terms

a(0) =1a(1) =-1a(2) =-1a(3) =0a(4) =2a(5) =1a(6) =-1a(7) =-4a(8) =-2a(9) =5a(10) =11a(11) =0a(12) =-21a(13) =-24a(14) =18a(15) =68a(16) =42a(17) =-100a(18) =-203a(19) =-17a(20) =428a(21) =521a(22) =-340a(23) =-1544a(24) =-1019a(25) =2252a(26) =4892a(27) =606a(28) =-10297a(29) =-13331