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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 25 |
| 3 | 160 |
| 4 | 1240 |
| 5 | 9417 |
| 6 | 71505 |
| 7 | 543155 |
| 8 | 4125662 |
| 9 | 31337363 |
| 10 | 238029974 |
| 11 | 1808010056 |
| 12 | 13733145621 |
| 13 | 104313185951 |
| 14 | 792334186609 |
| 15 | 6018351922536 |
| 16 | 45713741090407 |
| 17 | 347228967561412 |
| 18 | 2637455457327040 |
| 19 | 20033384133349773 |
| 20 | 152168059831839593 |
[1,25,160,1240,9417,71505,543155,4125662,31337363, 238029974,1808010056,13733145621,104313185951, 792334186609,6018351922536,45713741090407, 347228967561412,2637455457327040, 20033384133349773,152168059831839593] |