Here is ChatGPTs answer

What would be a simplified formula for a sequence like this:

n*10^0+n*10^1+n*10^2+n*10^3…

The given sequence can be written in sigma notation as:

∑(n*10^k) for k=0 to infinity

where ∑ represents the summation operator and k is the index variable that ranges from 0 to infinity.

Using the formula for the sum of an infinite geometric series, we can simplify the above expression as:

∑(n*10^k) for k=0 to infinity = n/(1-10) * ∑(10^k) for k=0 to infinity

= n/-9 * (1/(1-10))

= n/9

Therefore, the simplified formula for the given sequence is n/9.