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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 12 |
| 3 | 45 |
| 4 | 170 |
| 5 | 644 |
| 6 | 2451 |
| 7 | 9365 |
| 8 | 35908 |
| 9 | 138104 |
| 10 | 532589 |
| 11 | 2058782 |
| 12 | 7975216 |
| 13 | 30951921 |
| 14 | 120326060 |
| 15 | 468473348 |
| 16 | 1826415556 |
| 17 | 7129330988 |
| 18 | 27860219331 |
| 19 | 108984557708 |
| 20 | 426730087879 |
| 21 | 1672310507262 |
| 22 | 6558840830680 |
| 23 | 25742937514814 |
| 24 | 101108341344396 |
| 25 | 397368218111003 |
[1,3,12,45,170,644,2451,9365,35908,138104,532589, 2058782,7975216,30951921,120326060,468473348, 1826415556,7129330988,27860219331,108984557708, 426730087879,1672310507262,6558840830680, 25742937514814,101108341344396,397368218111003] |