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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 15 |
| 5 | 49 |
| 6 | 169 |
| 7 | 605 |
| 8 | 2226 |
| 9 | 8364 |
| 10 | 31956 |
| 11 | 123770 |
| 12 | 484862 |
| 13 | 1917800 |
| 14 | 7648470 |
| 15 | 30722318 |
| 16 | 124180334 |
| 17 | 504720369 |
| 18 | 2061489396 |
| 19 | 8457050387 |
| 20 | 34831589583 |
| 21 | 143972841512 |
| 22 | 597034531410 |
| 23 | 2483173470124 |
| 24 | 10356092457386 |
| 25 | 43298360910159 |
[1,1,2,5,15,49,169,605,2226,8364,31956,123770, 484862,1917800,7648470,30722318,124180334, 504720369,2061489396,8457050387,34831589583, 143972841512,597034531410,2483173470124, 10356092457386,43298360910159] |