Expansion of Product_{k>=1} (1 + 5^(k-1)*x^k).

Terms

a(0) =1a(1) =1a(2) =5a(3) =30a(4) =150a(5) =875a(6) =4500a(7) =25625a(8) =131250a(9) =750000a(10) =3843750a(11) =21562500a(12) =112109375a(13) =621093750a(14) =3222656250a(15) =17880859375a(16) =92578125000a(17) =508300781250