G.f. satisfies: A(x) = exp( Sum_{n>=1} x^n/n * Product_{d|n} A(d*x^n)^d ).

Terms

a(0) =1a(1) =1a(2) =2a(3) =4a(4) =11a(5) =24a(6) =73a(7) =171a(8) =500a(9) =1276a(10) =3698a(11) =9588a(12) =28119a(13) =75094a(14) =217835a(15) =599077a(16) =1736639a(17) =4842231a(18) =14092249a(19) =39844806a(20) =116011719a(21) =331986975a(22) =969188079a(23) =2796468133a(24) =8188982136a(25) =23798219204a(26) =69884802788a(27) =204303838580a(28) =601666227876