content: //   The Computer Language Shootout
  //   http://shootout.alioth.debian.org/
  //   contributed by Isaac Gouy
  
  import java.lang.Math;
  
  class partialsums {
     static final double twothirds = 2.0/3.0;
  
     public static void main(String[] args){
        int n = Integer.parseInt(args[0]);
  
        double a1 = 0.0, a2 = 0.0, a3 = 0.0, a4 = 0.0, a5 = 0.0;
        double a6 = 0.0, a7 = 0.0, a8 = 0.0, a9 = 0.0, alt = -1.0;
  
        for (int k=1; k<=n; k++){
           double k2 = (double)k * (double)k, k3 = k2 * (double)k;
           double sk = Math.sin(k), ck = Math.cos(k);
           alt = -alt;
  
           a1 += Math.pow(twothirds,k-1);
           a2 += 1.0/Math.sqrt(k);
           a3 += 1.0/(k*(k+1.0));
           a4 += 1.0/(k3 * sk*sk);
           a5 += 1.0/(k3 * ck*ck);
           a6 += 1.0/k;
           a7 += 1.0/k2;
           a8 += alt/k;
           a9 += alt/(2.0*k -1.0);
        }
        System.out.printf("%.9f\t(2/3)^k\n", a1);
        System.out.printf("%.9f\tk^-0.5\n", a2);
        System.out.printf("%.9f\t1/k(k+1)\n", a3);
        System.out.printf("%.9f\tFlint Hills\n", a4);
        System.out.printf("%.9f\tCookson Hills\n", a5);
        System.out.printf("%.9f\tHarmonic\n", a6);
        System.out.printf("%.9f\tRiemann Zeta\n", a7);
        System.out.printf("%.9f\tAlternating Harmonic\n", a8);
        System.out.printf("%.9f\tGregory\n", a9);
     }
  }
  