Expansion of Product_{k>=1} (1 + x^k)^(3^(k-1)).

Terms

a(0) =1a(1) =1a(2) =3a(3) =12a(4) =39a(5) =138a(6) =469a(7) =1603a(8) =5427a(9) =18372a(10) =61869a(11) =207909a(12) =696537a(13) =2328039a(14) =7762266a(15) =25826142a(16) =85749969a(17) =284171598a(18) =940027872a(19) =3104280885a(20) =10234808334a(21) =33692547249a(22) =110753171784a(23) =363561071175