Coefficients of the solution to a functional equation.

Terms

a(0) =1a(1) =3a(2) =6a(3) =9a(4) =12a(5) =18a(6) =27a(7) =27a(8) =15a(9) =36a(10) =108a(11) =54a(12) =-207a(13) =81a(14) =1296a(15) =81a(16) =-5397a(17) =45a(18) =25245a(19) =108a(20) =-118053a(21) =324a(22) =563355a(23) =162a(24) =-2711799a(25) =-621a(26) =13188096a(27) =243a(28) =-64689894a(29) =3888