Sum the series 9+99+999+9999+...to n terms?

or:Sum the series 9+99+999+9999+...to n terms?or:If n=10 then it becomes 100 + 1000 ... +10^9 = 1,111,111,110Any other value for n is not so simple.o

or:Sum the series 9+99+999+9999+...to n terms?

or:If n=10 then it becomes 100 + 1000 ... +10^9 = 1,111,111,110Any other value for n is not so simple.

or:Sum(10^k,k=0:n) - (n + 1) = (10 ^ (n+1) - 1) / (10 - 1) - (n + 1)Formula is here:math.stackexchange.com/questions/1929159/is-there-any-way-to-express-sum-i-1n-i-10i-1-without-sum

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