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| n | a(n) |
|---|---|
| 1 | 13 |
| 2 | 338 |
| 3 | 639 |
| 4 | 2974 |
| 5 | 15780 |
| 6 | 85681 |
| 7 | 461894 |
| 8 | 2501104 |
| 9 | 13632039 |
| 10 | 74052393 |
| 11 | 402461304 |
| 12 | 2191865388 |
| 13 | 11921228286 |
| 14 | 64849845095 |
| 15 | 352971589737 |
| 16 | 1920427592045 |
| 17 | 10448975722238 |
| 18 | 56861941373875 |
| 19 | 309398162988521 |
| 20 | 1683518039170569 |
[13,338,639,2974,15780,85681,461894,2501104, 13632039,74052393,402461304,2191865388, 11921228286,64849845095,352971589737, 1920427592045,10448975722238,56861941373875, 309398162988521,1683518039170569] |