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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 9 |
| 4 | 34 |
| 5 | 125 |
| 6 | 498 |
| 7 | 1995 |
| 8 | 8275 |
| 9 | 34635 |
| 10 | 147828 |
| 11 | 635203 |
| 12 | 2764589 |
| 13 | 12100073 |
| 14 | 53407392 |
| 15 | 236872232 |
| 16 | 1056879553 |
| 17 | 4734289388 |
| 18 | 21303849938 |
| 19 | 96179139060 |
| 20 | 435755416559 |
| 21 | 1979716310445 |
| 22 | 9019780037245 |
| 23 | 41191397377348 |
| 24 | 188552701333284 |
| 25 | 864826450474272 |
| 26 | 3974462412630393 |
| 27 | 18296975043799806 |
[1,1,3,9,34,125,498,1995,8275,34635,147828,635203, 2764589,12100073,53407392,236872232,1056879553, 4734289388,21303849938,96179139060,435755416559, 1979716310445,9019780037245,41191397377348, 188552701333284,864826450474272,3974462412630393, 18296975043799806] |