G.f. A(x) satisfies: A(x) = 1 + x + x^2 + x^3 + x^4 * A(x/(1 - x)) / (1 - x)^2.

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =3a(6) =7a(7) =15a(8) =31a(9) =65a(10) =147a(11) =373a(12) =1051a(13) =3157a(14) =9761a(15) =30573a(16) =96965a(17) =313999a(18) =1049719a(19) =3654303a(20) =13284783a(21) =50268837a(22) =196638987a(23) =789611161a(24) =3238765671a(25) =13540348965a(26) =57710600953a(27) =251163156089