Is it permissible to share in the Udhiyah (sacrifice) of one cow on behalf of oneself and one's deceased father, or is it permissible to share on behalf of the deceased only, without the sacrificer sharing?

The majority of scholars hold that a cow suffices as an Udhiyah for seven people. According to the Hanbalis and Hanafis, it is permissible for a person to offer one-seventh of a cow as a sacrifice for himself and a similar portion for his deceased father. However, the Shafi'is do not consider sacrifice on behalf of the deceased permissible unless the deceased had specifically willed it. Some scholars are of the opinion that it is better for a person to give charity on behalf of his father and dedicate the reward to him, because giving charity on behalf of the deceased is authentically reported from the Prophet, peace and blessings be upon him, unlike offering Udhiyah.