-131070domain: ZAppears in sequencesa(0)=1, a(n) = 2 - 2^(n-1) for n>0.at n=18A122958a(0) = 1, a(n) = (-1)^n*(2-2^(n-1)) for n>0.at n=18A122959Write x/(1-x) in the form Sum_{j>=1} a(j)*x^j/(1+a(j)*x^j).at n=33A290971