Answer: It looks like there is a typo in the question, as there is an extra comma and the term x1 is not defined. However, assuming that it should read a_n = (n+1)^x, we can proceed as follows:
To find a1, we simply plug in n = 1 into the formula for a_n:
a1 = (1+1)^x = 2^x
Therefore, the value of a1 depends on the value of x.