Express the accumulated amount in the bank as an explicit formula

Suppose I earn 500 dollars every month. If I deposit my monthly income fully into the bank, the bank pays interest of 0.25 % per month on the accumulated amount from the previous month.

For example:
Assuming n=months,

January, n=1, the accumulated amount would be $500

February, n=2, the accumulated amount would be $500 * 1.0025 + $500 = $1001.25

How do I find the explicit formula for the accumulated amount?