Outputting all balanced bracket expressions

brackets.js

outputBalancedBracket(3);

function outputBalancedBracket(n) {
    for (var i=1; i<=n; ++i) {
        var outputs = [];
        brackets("",0,0,i,outputs);
        console.log("N="+i+" "+outputs.join(','));
    }
}

function brackets(output, num_open, num_close, num_pairs, outputs) {
    if ((num_open == num_pairs) && (num_close == num_pairs)) {
        outputs.push(output);
    }
    else {
        if (num_open < num_pairs)
            brackets(output + "[", num_open + 1, num_close, num_pairs, outputs);
        if (num_close < num_open)
            brackets(output + "]", num_open, num_close + 1, num_pairs, outputs);
    }
}