An O(MG) version of Fibonacci on Node.js

gag.js

function fibonnaci(n, done) {
    if (n === 1 || n === 2) {
        done(1);
    } else {
        process.nextTick(function() {
            fibonnaci(n - 1, function(val1) {
                process.nextTick(function() {
                    fibonnaci(n - 2, function(val2) {
                        done(val1 + val2);
                    });
                });
            });
        });
    }
};


fibonnaci(20, function(val) {
    console.log('Final value ' + val);
});