Riordan array (1/(1+x), x(1-x)/(1+x)^2).

Terms

a(0) =1a(1) =-1a(2) =1a(3) =1a(4) =-4a(5) =1a(6) =-1a(7) =9a(8) =-7a(9) =1a(10) =1a(11) =-16a(12) =26a(13) =-10a(14) =1a(15) =-1a(16) =25a(17) =-70a(18) =52a(19) =-13a(20) =1a(21) =1a(22) =-36a(23) =155a(24) =-190a(25) =87a(26) =-16a(27) =1a(28) =-1a(29) =49