Tom K. answered 03/10/21
Knowledgeable and Friendly Math and Statistics Tutor
The answer is e10.
Think of the Taylor series for ex about 0. The derivative of all orders is ex , which is 1 evaluated at x = 0. Sum this and you can verify. So you don't have overflow issues, start with 1 at n= 0 and multiply the preceding term by 10/n. Add 40 terms and you will be convinced.