function binomial(n, p, filename)
  q = 1 - p;
  p = p/10
  output = fopen(filename, "w");
  while(k < n)
k = k + 0.1
    fprintf(output, "%d %f\n", k, bincoeff(n, k) * p**k * q**(n - k));
  endwhile
  fclose(output);
endfunction