'Seventy seven' in the Bible

If seven lives are to be taken as punishment for Cain's death, seventy-seven will be taken for Lamech's.

And all the years of Lamech's life were seven hundred and seventy-seven: and he came to his end.

And taking prisoner a young man of the people of Succoth, he got from him, in answer to his questions, a list of the chiefs of Succoth and the responsible men, seventy-seven men.

And those who had been prisoners, who had come back from a strange land, made burned offerings to the God of Israel, twelve oxen for all Israel, ninety-six male sheep, seventy-seven lambs, twelve he-goats for a sin-offering: all this was a burned offering to the Lord.