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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 9 |
| 3 | 18 |
| 4 | 83 |
| 5 | 245 |
| 6 | 914 |
| 7 | 3155 |
| 8 | 11287 |
| 9 | 39850 |
| 10 | 141325 |
| 11 | 501819 |
| 12 | 1782870 |
| 13 | 6328399 |
| 14 | 22463277 |
| 15 | 79770690 |
| 16 | 283288919 |
| 17 | 1005900951 |
| 18 | 3571642082 |
| 19 | 12682562591 |
| 20 | 45035370321 |
| 21 | 159915993486 |
| 22 | 567839908711 |
| 23 | 2016337387209 |
| 24 | 7159825934978 |
[1,9,18,83,245,914,3155,11287,39850,141325,501819, 1782870,6328399,22463277,79770690,283288919, 1005900951,3571642082,12682562591,45035370321, 159915993486,567839908711,2016337387209, 7159825934978] |