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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 17 |
| 5 | 101 |
| 6 | 402 |
| 7 | 1275 |
| 8 | 3921 |
| 9 | 14114 |
| 10 | 58601 |
| 11 | 243695 |
| 12 | 950578 |
| 13 | 3537847 |
| 14 | 13166791 |
| 15 | 50514102 |
| 16 | 198627921 |
| 17 | 782913717 |
| 18 | 3054480306 |
| 19 | 11824753551 |
| 20 | 45823049817 |
| 21 | 178682390994 |
| 22 | 700285942731 |
| 23 | 2747647985241 |
| 24 | 10767833451954 |
| 25 | 42164261091351 |
| 26 | 165225573240651 |
[1,1,1,2,17,101,402,1275,3921,14114,58601,243695, 950578,3537847,13166791,50514102,198627921, 782913717,3054480306,11824753551,45823049817, 178682390994,700285942731,2747647985241, 10767833451954,42164261091351,165225573240651] |