Ikrimah (may Allah have mercy on him) narrates from Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) slaughtered one ram each as aqiqah on behalf of Hasan and Husayn (may Allah be pleased with them both).
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الضحايا / 19283