1: #include <stdio.h>
2: #include <math.h>
3: 4: int main()
5: {6: double sum = 0;
7: int i;
8: for (i = 1; i <= 64; ++i)
9: { 10: sum += pow(2, i-1); 11: }12: printf("the sum is \n%f\n", sum);
13: 14: return 0;
15: }