a(n) = (-10)^n + 1 - 0^n.

Terms

a(0) =1a(1) =-9a(2) =101a(3) =-999a(4) =10001a(5) =-99999a(6) =1000001a(7) =-9999999a(8) =100000001a(9) =-999999999a(10) =10000000001a(11) =-99999999999