G.f.: A(x) = Product_{n>=1} 1/(1 - 5^n*x^n)^(5/5^n).

Terms

a(0) =1a(1) =5a(2) =30a(3) =155a(4) =855a(5) =4305a(6) =23255a(7) =116705a(8) =614655a(9) =3108355a(10) =16168430a(11) =81136755a(12) =422279580a(13) =2116775030a(14) =10893334980a(15) =54857686305a(16) =281413208380