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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 1 |
| 5 | 3 |
| 6 | 13 |
| 7 | 75 |
| 8 | 543 |
| 9 | 4719 |
| 10 | 47871 |
| 11 | 555177 |
| 12 | 7245015 |
| 13 | 105069249 |
| 14 | 1676322369 |
| 15 | 29178875913 |
| 16 | 550266979833 |
| 17 | 11176051287627 |
| 18 | 243213176948013 |
| 19 | 5645877335588331 |
| 20 | 139257558038636847 |
| 21 | 3636985088689068231 |
| 22 | 100266394939348499127 |
| 23 | 2909740575643004791953 |
| 24 | 88664517647380019280375 |
[1,1,1,1,3,13,75,543,4719,47871,555177,7245015, 105069249,1676322369,29178875913,550266979833, 11176051287627,243213176948013,5645877335588331, 139257558038636847,3636985088689068231, 100266394939348499127,2909740575643004791953, 88664517647380019280375] |