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| n | a(n) |
|---|---|
| 1 | 6 |
| 2 | 28 |
| 3 | 120 |
| 4 | 496 |
| 5 | 672 |
| 6 | 8128 |
| 7 | 523776 |
| 8 | 33550336 |
| 9 | 459818240 |
| 10 | 1476304896 |
| 11 | 8589869056 |
| 12 | 14182439040 |
| 13 | 31998395520 |
| 14 | 51001180160 |
| 15 | 137438691328 |
| 16 | 518666803200 |
| 17 | 13661860101120 |
| 18 | 30823866178560 |
| 19 | 740344994887680 |
| 20 | 796928461056000 |
| 21 | 212517062615531520 |
| 22 | 2305843008139952128 |
[6,28,120,496,672,8128,523776,33550336,459818240, 1476304896,8589869056,14182439040,31998395520, 51001180160,137438691328,518666803200, 13661860101120,30823866178560,740344994887680, 796928461056000,212517062615531520, 2305843008139952128] |