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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 3 |
| 4 | 13 |
| 5 | 71 |
| 6 | 461 |
| 7 | 3447 |
| 8 | 29093 |
| 9 | 273343 |
| 10 | 2829325 |
| 11 | 31998903 |
| 12 | 392743957 |
| 13 | 5201061455 |
| 14 | 73943424413 |
| 15 | 1123596277863 |
| 16 | 18176728317413 |
| 17 | 311951144828863 |
| 18 | 5661698774848621 |
| 19 | 108355864447215063 |
| 20 | 2181096921557783605 |
| 21 | 46066653228356851631 |
| 22 | 1018705098450570562877 |
[1,1,1,3,13,71,461,3447,29093,273343,2829325, 31998903,392743957,5201061455,73943424413, 1123596277863,18176728317413,311951144828863, 5661698774848621,108355864447215063, 2181096921557783605,46066653228356851631, 1018705098450570562877] |