// Report densities of simple oblique packing.
#include <stdio.h>
#include <math.h>
double pi;
double fac(double x){
  if (x==0) return 1;
  if(x==-0.5) return sqrt(pi);
  return x*fac(x-1);}

int main(){pi = 4*atan(1);
  for(int n=0; n<=24; ++n) printf ("%2d %e\n", n,
    exp(n/2.*log(pi/2.))/(fac(n/2.)*sqrt(n+1)));
  return 0;}

/*
 0 1.000000e+00
 1 1.000000e+00
 2 9.068997e-01
 3 7.404805e-01
 4 5.517277e-01
 5 3.798813e-01
 6 2.441515e-01
 7 1.476489e-01
 8 8.455650e-02
 9 4.609806e-02
10 2.402823e-02
11 1.201847e-02
12 5.786488e-03
13 2.688948e-03
14 1.208824e-03
15 5.267991e-04
16 2.229534e-04
17 9.178457e-05
18 3.680773e-05
19 1.439750e-05
20 5.499537e-06
21 2.053627e-06
22 7.504107e-07
23 2.685649e-07
24 9.421750e-08
*/