G.f. satisfies: A(x) = Sum_{n>=0} x^n * Product_{k=1..n} A(x^k).

Terms

a(0) =1a(1) =1a(2) =2a(3) =4a(4) =9a(5) =19a(6) =43a(7) =93a(8) =207a(9) =453a(10) =1003a(11) =2200a(12) =4860a(13) =10681a(14) =23552a(15) =51819a(16) =114186a(17) =251326a(18) =553634a(19) =1218857a(20) =2684461a(21) =5910729a(22) =13016952a(23) =28662693a(24) =63120135a(25) =138991543a(26) =306076520a(27) =673995311a(28) =1484205869a(29) =3268315926