Riordan array (1/(1+4x+x^2), x/(1+4x+x^2)).

Terms

a(0) =1a(1) =-4a(2) =1a(3) =15a(4) =-8a(5) =1a(6) =-56a(7) =46a(8) =-12a(9) =1a(10) =209a(11) =-232a(12) =93a(13) =-16a(14) =1a(15) =-780a(16) =1091a(17) =-592a(18) =156a(19) =-20a(20) =1a(21) =2911a(22) =-4912a(23) =3366a(24) =-1200a(25) =235a(26) =-24a(27) =1a(28) =-10864a(29) =21468