Expansion of g.f. A(x) satisfying 1 = Sum_{n=-oo..+oo} (-1)^n * x^n * (A(x) + x^(3*n-1))^(n+1).

Terms

a(0) =1a(1) =1a(2) =1a(3) =3a(4) =7a(5) =13a(6) =25a(7) =52a(8) =111a(9) =235a(10) =495a(11) =1054a(12) =2271a(13) =4923a(14) =10703a(15) =23354a(16) =51190a(17) =112668a(18) =248783a(19) =550875a(20) =1223107a(21) =2722766a(22) =6075619a(23) =13586390a(24) =30442616a(25) =68339788a(26) =153683822a(27) =346173172a(28) =780948750a(29) =1764312745