"In the twenty-ninth jubilee, in the first week, in the beginning thereof Arpachshad took to himself a wife and her name was Rasu'eja, the daughter of Susan, the daughter of Elam, and she bare him a son in the third year in this week, and he called his name Kainam.
And the son grew, and his father taught him writing, and he went to seek for himself a place where he might seize for himself a city.
And he found a writing which former (generations) had carved on the rock, and he read what was thereon, and he transcribed it and sinned owing to it; for it contained the teaching of the Watchers in accordance with which they used to observe the omens of the sun and moon and stars in all the signs of heaven.
"In the twenty-ninth jubilee, in the first week, in the beginning thereof Arpachshad took to himself a wife and her name was Rasu'eja, the daughter of Susan, the daughter of Elam, and she bare him a son in the third year in this week, and he called his name Kainam.
And the son grew, and his father taught him writing, and he went to seek for himself a place where he might seize for himself a city.
And he found a writing which former (generations) had carved on the rock, and he read what was thereon, and he transcribed it and sinned owing to it; for it contained the teaching of the Watchers in accordance with which they used to observe the omens of the sun and moon and stars in all the signs of heaven.
https://www.pseudepigrapha.com/jubilees/8.htm