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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 25 |
| 3 | 133 |
| 4 | 929 |
| 5 | 6134 |
| 6 | 40873 |
| 7 | 272012 |
| 8 | 1810626 |
| 9 | 12051365 |
| 10 | 80215518 |
| 11 | 533919483 |
| 12 | 3553810073 |
| 13 | 23654434010 |
| 14 | 157445726657 |
| 15 | 1047970872960 |
| 16 | 6975374721128 |
| 17 | 46428630555399 |
| 18 | 309032535648912 |
| 19 | 2056944323309905 |
| 20 | 13691179605401845 |
[1,25,133,929,6134,40873,272012,1810626,12051365, 80215518,533919483,3553810073,23654434010, 157445726657,1047970872960,6975374721128, 46428630555399,309032535648912,2056944323309905, 13691179605401845] |