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

Terms

a(0) =1a(1) =1a(2) =2a(3) =5a(4) =10a(5) =20a(6) =43a(7) =93a(8) =194a(9) =403a(10) =842a(11) =1755a(12) =3656a(13) =7643a(14) =15976a(15) =33281a(16) =69164a(17) =143558a(18) =297619a(19) =616625a(20) =1277729a(21) =2647861a(22) =5485300a(23) =11356731a(24) =23495794a(25) =48567063a(26) =100301668a(27) =206994479a(28) =426941231a(29) =880227976