Riordan array (-sqrt(4*x^2+8*x+1)+2*x+2, (sqrt(4*x^2+8*x+1)-2*x-1)/2).

Terms

a(0) =1a(1) =-2a(2) =1a(3) =6a(4) =-5a(5) =1a(6) =-24a(7) =24a(8) =-8a(9) =1a(10) =114a(11) =-123a(12) =51a(13) =-11a(14) =1a(15) =-600a(16) =672a(17) =-312a(18) =87a(19) =-14a(20) =1a(21) =3372a(22) =-3858a(23) =1914a(24) =-618a(25) =132a(26) =-17a(27) =1a(28) =-19824a(29) =22992