G.f. A(x) satisfies: A(x) = 1 / (1 - x + x^3 * A(x)).

Terms

a(0) =1a(1) =1a(2) =1a(3) =0a(4) =-2a(5) =-5a(6) =-7a(7) =-4a(8) =10a(9) =38a(10) =70a(11) =68a(12) =-40a(13) =-329a(14) =-767a(15) =-1012a(16) =-214a(17) =2842a(18) =8642a(19) =14332a(20) =10136a(21) =-21622a(22) =-96578a(23) =-196412a(24) =-213080a(25) =96264a(26) =1037344a(27) =2608788a(28) =3698996a(29) =1121127