Aggregate in Sync order

gistfile1.js

var ids = [1,2,3]; 

var aggregateIds = function(ids, obj, callback){
	var id; 
	if(!obj){
		obj = {}; 
	}
	if(ids.length){
		setTimeout(function(){
			var id = ids.shift(); 
			obj[id] = id;  
			aggregateIds(ids, obj, callback);
		}, 500); 
	} else {
		return callback(null, obj); 
	}
}

aggregateIds([1,3,4], null, function(error, result){
  console.log("%j", result); 	
});