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

Terms

a(0) =1a(1) =1a(2) =2a(3) =5a(4) =16a(5) =50a(6) =177a(7) =608a(8) =2205a(9) =7948a(10) =29552a(11) =109554a(12) =414342a(13) =1568627a(14) =6011290a(15) =23102857a(16) =89512855a(17) =347930789a(18) =1360252177a(19) =5334715764a(20) =21012372520a(21) =83004307780a(22) =328996301835