I don't understand your math to begin with.
There are 24*365 = roughly 8760 hours in a year. A block every 10 minutes, 8760*6 = 52560 blocks.
52560 * 50 = 2628000 Bitcoins?
If Bitcoin delivered 50 coins every 10 minutes (600 seconds) the first year, then it should have delivered 50 x (1577000/10) = 7885000 Bitcoin the first yea
Where do you get this formula from?
If you account the increase/decrease in hash rate, (or the lack of blocks mined in the first year of bitcoin "existing",) this number may vary slighly when looking on a shorter period of time, otherwise, this should be pretty correct?