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

Terms

a(0) =1a(1) =1a(2) =2a(3) =5a(4) =11a(5) =26a(6) =64a(7) =158a(8) =399a(9) =1027a(10) =2675a(11) =7052a(12) =18788a(13) =50487a(14) =136711a(15) =372687a(16) =1021942a(17) =2816873a(18) =7800510a(19) =21691134a(20) =60543553a(21) =169561453a(22) =476351239a(23) =1342002198a(24) =3790565335a(25) =10732246631a(26) =30453309502a(27) =86589559266a(28) =246672752090