Remember the definition of the Josephus problem: a group of men gather in a circle, and every alternate person kills himself, starting with person number 2. Our job is to figure out the last person left standing.
If there are n people in the circle, then we use the notation J(n) to represent the last person left standing. For example, if there are only 2 people, then person number 2 kills himself, and person number 1 is left. Our short-hand representation of this fact is to write J(2)=1.
To take another example, if there are 3 people in the circle, then first person number 2 kills himself, then person number 1, so person number 3 is the last person left alive. Our concise representation of this is to write J(3)=3.
| n | J(n) |
|---|---|
| 2 | 1 |
| 3 | 3 |
| 4 | |
| 5 | |
| 6 | |
| 7 | |
| 8 | |
| 9 | |
| 10 | |
| 11 | |
| 12 | |
| 13 | |
| 14 | |
| 15 | |
| 16 | |
| 17 | |
| 18 | |
| 19 | |
| 20 | |
| 41 |
fmwww.bc.edu/MT/gross/NumEx13a.html
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