sorry if im not posting this in the right place

i though this would be pretty straightforward

an employee starts work on an annual salary of $30 000. His pay scale will give him an increase of $800 per annum on 1 January until 1 January 2015 inclusive. He remains on this salary until he retires on 31 December 2040. How much will he earn during his working life?

ok so the sum of the first 15 years is 0.5n(2a+d(n-1)) = 7.5 (60000 + 800 x 14) = 534 000

his final salary l = a+d(n-1) = 41 200

he will earn this every year for 25 years.

so he will earn on total 534 000 + (41 200 x 25)

=1 564 000

this is wrong

the real answer is $1 626 000

how do i get to that? where is the mistake in my calculations?