Minimizing the Largest Term of an Increasing Sequence

Suppose $a_1<a_2<\cdots<a_{25}$ are positive integers such that the average of $a_1,a_2,\ldots,a_{24}$ is one-half the average of $a_1,a_2,\ldots,a_{25}$. What is the minimum possible value of $a_{25}$?