Write 2*x/(1-x) in the form Sum_{j>=1} ((1-x^j)^a(j) - 1).

Terms

a(0) =-2a(1) =1a(2) =2a(3) =3a(4) =4a(5) =6a(6) =6a(7) =10a(8) =8a(9) =15a(10) =10a(11) =25a(12) =12a(13) =28a(14) =10a(15) =60a(16) =16a(17) =25a(18) =18a(19) =125a(20) =0a(21) =66a(22) =22a(23) =218a(24) =24a(25) =91a(26) =-30a(27) =420a(28) =28a(29) =-387