What is the established number of rak'ahs performed by 'Abdullah ibn 'Umar after the Jumu'ah prayer?

Primary text

Abdullah ibn 'Umar observed a man praying two rak'ahs after Jumu'ah and moved him, questioning if he was praying four rak'ahs. However, 'Abdullah himself used to pray two rak'ahs in his house after Jumu'ah, stating that this is what the Messenger of Allah, peace be upon him, did.