You can use Dictionary>
Dictionary associate a key to a value, like an physical Dictionary book.
Dictionary> myDict = new Dictionary>();
for (int i = 0; i < infoForUserSessions.Count; ++i){
myDict.add("user" + i, new List());
}
Here is an exemple how to use Dictionary :
Dictionary myDict = new Dictionary();
//Line below will add both KEY and a VALUE to the dictionary, BOTH are linked one to eachother
myDict.add("apple", "Apple is a brand");
//This above line return "Apple is a brand"
myDict["apple"];