Find the lowest positive integer that has its digits reversed after dividing it by 2.

After trying to work it out arithmetically by the possible first/last digit combinations, I found nothing.

I decided to try to find one, anyway, just for the heck of it. The following javascript found nothing:

<script>
function reverse(x) {
  xstr = x.toString();
  str = "";
  for (var d = xstr.length; d >= 0; --d)
  {
    str += xstr.charAt(d);
  }
  return str;
}

function doPal(x) {
  double = 2*x;
  if (double == reverse(x)) {
    document.write(x + " " + double + "<br>");
    return true;
  }
  return false;
}

for (var i = 1; i < 10000000; i++)
  doPal(i);
</script>

Posted by DJ on 2004-07-15 17:45:21