/*
 * Calculate Basel sum
 */

#include <stdio.h>
#include <math.h>

#define N 10000
#define REP 19

double baselsum(long m) {
    long n;
    double s = 0.;
    for(n=1; n<=m; n++) {
        s += 1/((double)n*n);
    }
    return(s);
}

int main(void) {
    long m;
    int i;
    double s, ans;

    ans = M_PI*M_PI/6;

    m = N;
    for (i = 0; i < REP; i++) {
        s = baselsum(m);
        printf("%20ld   %20.14f %20.14f  %20.14f\n", m, s, ans, ans-s);
        m *= 2;
    }

    return(0);
}