Define an array, data, with 100 elements of type double. Write a loop that will store the following sequence of values in corresponding elements of the array:
1/(2*3*4) 1/(4*5*6) 1/(6*7*8) … up to 1/(200*201*202)

Write another loop that will calculate the following:
data[0]-data[1]+data[2]-data[3]+… -data[99]

Multiply the result of this by 4.0, add 3.0, and output the final result.

Do you recognize the value that you get?

#include <stdio.h>

void main(void)
{
	int i;	// counter
	double data[100]; 
	double sum = 0.0;
	double sign = 1.0;


	for(i = 1 ; i<=100 ; i++)
    		data[i-1] = 1.0/(2*i*(2*i+1)*(2*i+2));

  	for(i = 0 ; i<100 ; i++)
  	{
    		sum += sign*data[i];
    		sign = -sign;
  	}

  	printf("\nThe result is %.4lf\n", 4.0*sum+3);
}