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| n | a(n) |
|---|---|
| 3 | 4128 |
| 4 | 45696 |
| 5 | 287160 |
| 6 | 2172480 |
| 7 | 11866848 |
| 8 | 76468352 |
| 9 | 390714840 |
| 10 | 2301083680 |
| 11 | 11288784144 |
| 12 | 62812654272 |
| 13 | 299720429528 |
| 14 | 1604776566400 |
| 15 | 7505573487360 |
| 16 | 39105991164160 |
| 17 | 180179056818584 |
| 18 | 920223907284960 |
| 19 | 4191443432295472 |
| 20 | 21088555826121280 |
| 21 | 95195388883597464 |
| 22 | 473503955161244480 |
[4128,45696,287160,2172480,11866848,76468352, 390714840,2301083680,11288784144,62812654272, 299720429528,1604776566400,7505573487360, 39105991164160,180179056818584,920223907284960, 4191443432295472,21088555826121280, 95195388883597464,473503955161244480] |