gistfile1.js

var symbols = '23456789QWERTYUPASDFGHJKZXCVBNM';
var qty = 1500000;
var length = 7;
var code, hash, i, maxIndex, rand, symbol, _i, _j;
maxIndex = symbols.length - 1;
for (i = _i = 1; 1 <= qty ? _i <= qty : _i >= qty; i = 1 <= qty ? ++_i : --_i) {
  code = 'KX ';
  hash = 0;
  for (symbol = _j = 1; 1 <= length ? _j <= length : _j >= length; symbol = 1 <= length ? ++_j : --_j) {
    rand = Math.floor((Math.random() * maxIndex) + 1);
    code += symbols[rand];
    hash += rand;
    if (hash > maxIndex) {
      hash = hash - maxIndex;
    }
  }
  code += symbols[hash];
  db.codes.insert({
    code: code,
    hash: symbols[hash]
  });
}