Expansion of Product_{k>=1} (1 + 6^(k-1)*x^k).

Terms

a(0) =1a(1) =1a(2) =6a(3) =42a(4) =252a(5) =1728a(6) =10584a(7) =71280a(8) =435456a(9) =2939328a(10) =17962560a(11) =119532672a(12) =739031040a(13) =4867527168a(14) =30051689472a(15) =198147658752