Expansion of Product_{k>=1} 1/(1 - x^k / (1 - k*x)).

Terms

a(0) =1a(1) =1a(2) =3a(3) =8a(4) =22a(5) =62a(6) =182a(7) =560a(8) =1822a(9) =6316a(10) =23467a(11) =93762a(12) =402989a(13) =1858904a(14) =9165303a(15) =48065800a(16) =266791060a(17) =1560140592a(18) =9573440644a(19) =61431041813a(20) =411006873603