Is it permissible to combine the children for the Aqiqah by slaughtering a large animal (badanah) instead of a number of sheep and distributing it among the neighborhood, and is it permissible for me to perform Aqiqah for myself, knowing that I do not know if my father performed Aqiqah for me?

The 'Aqiqah is a confirmed Sunnah obligatory upon the father. Its origin is the action of the Prophet, peace and blessings be upon him. It is performed on the seventh day of the newborn's life, otherwise on the fourteenth, or the twenty-first. It is permissible to perform it at any time thereafter. The father performs the 'Aqiqah for his children before they reach puberty, and after puberty, the obligation falls from him. It is permissible for the children to perform the 'Aqiqah for themselves. It is not valid to include all children in a single large animal (badanah), and there is no objection to a person performing the 'Aqiqah for himself.