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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 25 |
| 3 | 31 |
| 4 | 247 |
| 5 | 799 |
| 6 | 4281 |
| 7 | 15751 |
| 8 | 61581 |
| 9 | 267037 |
| 10 | 1298599 |
| 11 | 5618731 |
| 12 | 25891377 |
| 13 | 121559461 |
| 14 | 569107129 |
| 15 | 2632371325 |
| 16 | 12330807475 |
| 17 | 58079266349 |
| 18 | 275266138925 |
| 19 | 1306176923689 |
| 20 | 6218631031361 |
| 21 | 29703202000153 |
| 22 | 142156751690535 |
[1,25,31,247,799,4281,15751,61581,267037,1298599, 5618731,25891377,121559461,569107129,2632371325, 12330807475,58079266349,275266138925, 1306176923689,6218631031361,29703202000153, 142156751690535] |