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

Terms

a(0) =1a(1) =9a(2) =27a(3) =73a(4) =125a(5) =243a(6) =343a(7) =585a(8) =729a(9) =1125a(10) =1331a(11) =1971a(12) =2197a(13) =3087a(14) =3375a(15) =4681a(16) =4913a(17) =6561a(18) =6859a(19) =9125a(20) =9261a(21) =11979a(22) =12167a(23) =15795a(24) =15625a(25) =19773a(26) =19683a(27) =25039a(28) =24389a(29) =30375