python - sum of cubes using formula : How to compute the sum of cubes of first 100 integers in Python using formula

    \frac{n^2(n+1)^2}{4}.

I've tried 

    s=0
    for n in range (0,1001):
        s+=(int)((n*(n+1))/2)**2
        print("Sum is:",s)
but it does not seem to work. 

Thank you for your time!