I have heard that the superstition of bad luck associated with the number 13 goes back to the Bible.
The twelve Apostles and Christ made 13 at the Last supper and possibly it began there, but that ignores that Jesus and the Apostles formed a group of 13 before that occasion.
The belief in bad luck befalling people on Friday 13th was in the past not associated with every Friday 13th. Only in the twentieth century did that superstition arise. Prior to the Twentieth Century only Good Friday (Friday between Palm Sunday and Easter Day) the traditional day of the Crucifiction was considered unlucky if it was Friday 13th. A much rarer occasion than today's belief.
The fear of the number 13 is also a recognized phobia, with the medical name, Triskadecaphobia.