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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 3 |
| 4 | 14 |
| 5 | 122 |
| 6 | 1538 |
| 7 | 28160 |
| 8 | 687216 |
| 9 | 21985504 |
| 10 | 877927620 |
| 11 | 43310174393 |
| 12 | 2579819875036 |
| 13 | 182645907850321 |
| 14 | 15166854447512754 |
| 15 | 1459204576675950496 |
| 16 | 161391028121114185561 |
| 17 | 20297024256655626819933 |
| 18 | 2880152675051053471691329 |
| 19 | 458990926597368013495650709 |
[1,1,3,14,122,1538,28160,687216,21985504, 877927620,43310174393,2579819875036, 182645907850321,15166854447512754, 1459204576675950496,161391028121114185561, 20297024256655626819933,2880152675051053471691329, 458990926597368013495650709] |