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

Terms

a(0) =1a(1) =1a(2) =2a(3) =4a(4) =10a(5) =26a(6) =73a(7) =211a(8) =629a(9) =1912a(10) =5913a(11) =18531a(12) =58739a(13) =187963a(14) =606416a(15) =1970326a(16) =6441623a(17) =21175056a(18) =69946082a(19) =232054411a(20) =772886274a(21) =2583325555a(22) =8662455004a(23) =29132638803a(24) =98240253058a(25) =332105822674