Riordan array (f(x), x*f(x)) where f(x) is the g.f. of A168491.

Terms

a(0) =1a(1) =-1a(2) =1a(3) =2a(4) =-2a(5) =1a(6) =-5a(7) =5a(8) =-3a(9) =1a(10) =14a(11) =-14a(12) =9a(13) =-4a(14) =1a(15) =-42a(16) =42a(17) =-28a(18) =14a(19) =-5a(20) =1a(21) =132a(22) =-132a(23) =90a(24) =-48a(25) =20a(26) =-6a(27) =1a(28) =-429a(29) =429