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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 13 |
| 3 | 325 |
| 4 | 8425 |
| 5 | 218713 |
| 6 | 5678101 |
| 7 | 147411901 |
| 8 | 3827031313 |
| 9 | 99355402225 |
| 10 | 2579413426525 |
| 11 | 66965393687413 |
| 12 | 1738520822446201 |
| 13 | 45134575989913801 |
| 14 | 1171760454915312613 |
| 15 | 30420637251808214125 |
| 16 | 789764808092098254625 |
| 17 | 20503464373142746406113 |
| 18 | 532300308893619308304301 |
[1,13,325,8425,218713,5678101,147411901, 3827031313,99355402225,2579413426525, 66965393687413,1738520822446201,45134575989913801, 1171760454915312613,30420637251808214125, 789764808092098254625,20503464373142746406113, 532300308893619308304301] |