G.f. A(x) satisfies: A(x)^5 = A(x^5) / (1 - 5*x).

Terms

a(0) =1a(1) =1a(2) =3a(3) =11a(4) =44a(5) =185a(6) =801a(7) =3547a(8) =15961a(9) =72710a(10) =334463a(11) =1550679a(12) =7236463a(13) =33955573a(14) =160075762a(15) =757689991a(16) =3599019810a(17) =17148240314a(18) =81930357294a(19) =392402777679