a(n) = (10^n-1)*(91/81)-n*10^n/9.

A064616

a(n) = (10^n-1)*(91/81)-n*10^n/9.

Terms

    a(0) =9a(1) =89a(2) =789a(3) =6789a(4) =56789a(5) =456789a(6) =3456789a(7) =23456789a(8) =123456789a(9) =123456789a(10) =-9876543211a(11) =-209876543211

External references