sub p {
  $n = shift;
  return (4/(8*$n+1)-2/(8*$n+4)-1/(8*$n+5)-1/(8*$n+6));
}

for $i (0..15) {
  $p = p($i);
  $c = $p*(1/16**$i);
  #print "$p\n";
  $t += $p * (1/16**$i);
  print "$t\n";
}
print "$t\n";