G.f. satisfies A(x) = exp( Sum_{k>=1} A(x^k) * x^k/(k * (1 + 2*x^k)) ).

Terms

a(0) =1a(1) =1a(2) =0a(3) =2a(4) =0a(5) =2a(6) =1a(7) =6a(8) =-2a(9) =11a(10) =-1a(11) =30a(12) =-21a(13) =76a(14) =-60a(15) =223a(16) =-245a(17) =653a(18) =-817a(19) =2031a(20) =-2935a(21) =6521a(22) =-10067a(23) =21455a(24) =-35425a(25) =72152a(26) =-123756a(27) =246752a(28) =-436854a(29) =855852