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| n | a(n) |
|---|---|
| 2 | 2 |
| 3 | 5 |
| 4 | 10 |
| 5 | 44 |
| 6 | 104 |
| 7 | 656 |
| 8 | 2624 |
| 9 | 15744 |
| 10 | 67584 |
| 11 | 694272 |
| 12 | 2777088 |
| 13 | 34062336 |
| 14 | 213221376 |
| 15 | 1758855168 |
| 16 | 14070841344 |
| 17 | 228530847744 |
| 18 | 1371185086464 |
| 19 | 25007480635392 |
| 20 | 200059845083136 |
| 21 | 2447683608379392 |
| 22 | 25040421692375040 |
| 23 | 556525133318062080 |
| 24 | 4452201066544496640 |
| 25 | 89044021330889932800 |
[2,5,10,44,104,656,2624,15744,67584,694272, 2777088,34062336,213221376,1758855168,14070841344, 228530847744,1371185086464,25007480635392, 200059845083136,2447683608379392, 25040421692375040,556525133318062080, 4452201066544496640,89044021330889932800] |