G.f. A(x) satisfies: [x^(n+1)] A(x)^n = n*([x^(n-1)] A(x)^n) for n>=1.

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =2a(5) =4a(6) =12a(7) =34a(8) =120a(9) =412a(10) =1608a(11) =6244a(12) =26288a(13) =111448a(14) =499256a(15) =2265288a(16) =10701896a(17) =51339768a(18) =254175048a(19) =1278947304a(20) =6604214760a(21) =34662182904a(22) =186002333640