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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 4 |
| 3 | 9 |
| 4 | 23 |
| 5 | 70 |
| 6 | 244 |
| 7 | 1015 |
| 8 | 4605 |
| 9 | 25090 |
| 10 | 137516 |
| 11 | 963589 |
| 12 | 5832243 |
| 13 | 54685670 |
| 14 | 310755964 |
| 15 | 4567695283 |
| 16 | 15162041017 |
| 17 | 581160322338 |
| 18 | -1133608829900 |
| 19 | 115627157052929 |
| 20 | -1056546484541681 |
| 21 | 34518230044201062 |
| 22 | -541838359813821916 |
| 23 | 14135169210980556655 |
| 24 | -288911084512245360587 |
[1,2,4,9,23,70,244,1015,4605,25090,137516,963589, 5832243,54685670,310755964,4567695283,15162041017, 581160322338,-1133608829900,115627157052929, -1056546484541681,34518230044201062, -541838359813821916,14135169210980556655, -288911084512245360587] |