time complexity

[SaifN]

Hi,

Can you help me figure out time complicity of this code:
func(n)
s←0;
for i←n to n^3
do
j←1;
while j < i^2
do
j←j×2;
s←s+j−i;
return(s);

thanks

[Smac89]

Outer loop runs n³ times. Each iteration of outer loop results in i² iterations of inner loop. So the number of times they run in total is the sum 1² -> n³^2
Formula to get this sum:
http://www.trans4mind.com/personal_development/mathematics/series/sumNaturalSquares.htm