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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 1 |
| 5 | 3 |
| 6 | 10 |
| 7 | 26 |
| 8 | 69 |
| 9 | 173 |
| 10 | 436 |
| 11 | 1084 |
| 12 | 2699 |
| 13 | 6699 |
| 14 | 16634 |
| 15 | 41274 |
| 16 | 102425 |
| 17 | 254137 |
| 18 | 630584 |
| 19 | 1564600 |
| 20 | 3882103 |
| 21 | 9632247 |
| 22 | 23899510 |
| 23 | 59299318 |
| 24 | 147133173 |
| 25 | 365065973 |
| 26 | 905799668 |
| 27 | 2247464948 |
| 28 | 5576397299 |
| 29 | 13836125171 |
[0,0,0,0,1,3,10,26,69,173,436,1084,2699,6699, 16634,41274,102425,254137,630584,1564600,3882103, 9632247,23899510,59299318,147133173,365065973, 905799668,2247464948,5576397299,13836125171] |