math b50
posted by sheri .
must answered in sequences/series formulas
If the profit earned by a company is $100 in the first year, and doubles each year such that the profit earned in the second year is $200, $400 in the third year and so on. Find the total profit earned by the company in 15 years of operation.

i have figured out on my calculator what the answer is but the answer wont work when i use a formula.. HELP

WIth first term of 100, common factor of 2 and number of years n = 15,
S = 100(2^15  1)/(2  1) =
or (100+200+400+800+16oo+3200+6400+12800+25600+51200+102400+204800+409800+819200+1638400)100 = 
1500