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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 19 |
| 5 | 85 |
| 6 | 496 |
| 7 | 3229 |
| 8 | 25117 |
| 9 | 215225 |
| 10 | 2100430 |
| 11 | 22187281 |
| 12 | 261228199 |
| 13 | 3284651245 |
| 14 | 45163266604 |
| 15 | 659277401525 |
| 16 | 10380194835601 |
| 17 | 172251467909809 |
| 18 | 3057368096689690 |
| 19 | 56867779157145769 |
| 20 | 1122474190194034555 |
| 21 | 23137433884903034501 |
| 22 | 502874858021076645784 |
[1,1,2,5,19,85,496,3229,25117,215225,2100430, 22187281,261228199,3284651245,45163266604, 659277401525,10380194835601,172251467909809, 3057368096689690,56867779157145769, 1122474190194034555,23137433884903034501, 502874858021076645784] |