Google Blockly - a visual programming language(code.google.com)

  var n;
  var A;
  var i;
  var x;
  var j;

  n = 100;
  A = [];
  for (i = 0; i <= n; i++) {
    A[i - 1] = true;
  }
  var i_end = Math.sqrt(n);
  for (i = 2; i <= i_end; i++) {
    if (A[i - 1] == true) {
      j = Math.pow(i, 2);
      while (j <= n) {
        A[j - 1] = false;
        j = (j || 0) + i;
      }
    }
  }
  for (x = 2; x <= n; x++) {
    window.alert([x,': ',A[x - 1]].join(''));
  }

     Number of one-bits in 1 bit numbers from 0 to 1 = 1
     Number of one-bits in 2 bit numbers from 0 to 3 = 4
     Number of one-bits in 3 bit numbers from 0 to 7 = 12
     Number of one-bits in 4 bit numbers from 0 to 15 = 32
     Number of one-bits in 5 bit numbers from 0 to 31 = 80
     Number of one-bits in 6 bit numbers from 0 to 63 = 192
     Number of one-bits in 7 bit numbers from 0 to 127 = 448
     ....

    var list;
    var x;
    var prev;
    var onebits;
    var doubleatprev;

    list = [];
    list[0] = 1;
    list[1] = 4;
    for (x = 2; x <= 20; x++) {
    prev = x;
    prev);
    doubleatprev = list[x - 1] * 2;
    list[1 + x - 1] = onebits + doubleatprev;
    }
    for (x = 1; x <= 20; x++) {
      window.alert(['Number of one-bits in ',x,' bit numbers    from 0 to ',Math.pow(2, x) - 1,' = ',list[x - 1]].join(''));
    }

    /**
     * Execute the user's code.  Heaven help us...
     */

  while (true) do
    if not (wall to the left) then
      (turn left)
    while (wall ahead) do
      (turn right)
    (move forward)