Question 893579
{{{9}}}.
{{{99=9+9*10}}}.
{{{999=9+9*10+9*10^2}}}.
Next would be:
{{{9999=9+9*10+9*10^2+9*10^3}}}.


9 uses n=1;
9999 uses n=4.



{{{9*sum(10^(i-1),i=1,n)}}}