G.f. satisfies: A(x) = exp( Sum_{n>=1} A(-x^n)^2 * x^n/n ).

Terms

a(0) =1a(1) =1a(2) =-1a(3) =-2a(4) =5a(5) =14a(6) =-40a(7) =-119a(8) =351a(9) =1083a(10) =-3291a(11) =-10424a(12) =32562a(13) =105066a(14) =-334666a(15) =-1094595a(16) =3536043a(17) =11686231a(18) =-38172425a(19) =-127199414a(20) =419230644a(21) =1406346735a(22) =-4669311299a(23) =-15750517780a(24) =52616257231a(25) =178312867791a(26) =-598779740235