Riordan array (1/(1-x), x/(1+x)).

Terms

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