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| n | a(n) |
|---|---|
| 4 | 3 |
| 5 | 30 |
| 6 | 270 |
| 7 | 2322 |
| 8 | 20772 |
| 9 | 195372 |
| 10 | 1958337 |
| 11 | 20933154 |
| 12 | 238789782 |
| 13 | 2900868876 |
| 14 | 37451986200 |
| 15 | 512534035080 |
| 16 | 7416327050415 |
| 17 | 113185393797510 |
| 18 | 1817654015037150 |
| 19 | 30647027466113094 |
| 20 | 541407973316966604 |
| 21 | 10001886705503187732 |
| 22 | 192877025408450517501 |
| 23 | 3876090406516703418282 |
[3,30,270,2322,20772,195372,1958337,20933154, 238789782,2900868876,37451986200,512534035080, 7416327050415,113185393797510,1817654015037150, 30647027466113094,541407973316966604, 10001886705503187732,192877025408450517501, 3876090406516703418282] |