maths
posted by Anonymous .
1*2 +2*(2^2)+2*(2^3)............+100*(2^100)
Find the sum of series.

1+x+x^2+...+x^n = (x^(n+1)1)/(x1)
Now I think the beginning of your sequence should be
2*2^0 + 2*2^1 + 2*2^2 + ...
In that case, the sum is 2*(2^1011)/(21) 
On the other hand, there could be only one typo and the series is
1(2^1) + 2(2^2) + 3(2^3 + ... + 100(2^100)
In that case you have a hypergeometric series ... 
I think I gotta go with Reiny. My answer is bogus because of the 100*2^100.
What was I thinking?