Flavius Josephus was a Jewish historian who lived in the first century CE. He was known for his works on Jewish history, including "The Jewish War" and "Antiquities of the Jews". But one of his most famous contributions to mathematics is a problem that bears his name.
According to the story, Flavius Josephus and 39 of his comrades were trapped in a cave by Roman soldiers during the Jewish War. The soldiers demanded that they surrender and be taken as slaves, but the Jews decided to kill themselves rather than be enslaved. They formed a circle and decided to kill every third person, with the last person left being the one who would take his own life.
Flavius Josephus, however, had a different plan. He quickly realized that if they followed the soldiers' instructions, he would be one of the last people left and would have to take his own life. So he proposed a new plan. He suggested that they arrange themselves in a circle and begin counting off from one. The person who reached the number three would be killed, and the count would continue from the next person. But instead of continuing in a circle, they would remove the person who was killed and start counting from the next person in line. In other words, they would skip over the dead person and continue counting from the next person.
This plan would ensure that Flavius Josephus would not be among the last people left, as he would always be one of the first three to be counted. And it worked. They followed his plan, and Flavius Josephus was one of the last two people left. He convinced the other person to surrender to the Romans rather than take his own life, and Flavius Josephus himself surrendered and became a slave of the Roman Empire.
The problem that Flavius Josephus proposed has become known as the Josephus Problem, and it has been studied in mathematics and computer science. It involves finding the position of the last person left in a circle of n people who are eliminated one by one according to a specific rule. The problem has applications in computer science, particularly in algorithms for data structures and search operations. It is also studied in game theory and combinatorics.