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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 1 |
| 3 | 1 |
| 4 | 5 |
| 5 | 5 |
| 6 | 49 |
| 7 | 118 |
| 8 | 121 |
| 9 | 2406 |
| 10 | 2698 |
| 11 | 4182 |
| 12 | 4946 |
| 13 | 153627 |
| 14 | 3087192 |
| 15 | 8203485 |
| 16 | 38394376 |
| 17 | 487844934 |
| 18 | 2822741576 |
| 19 | 4140154385 |
| 20 | 4397137572 |
| 21 | 8583966231 |
[0,1,1,5,5,49,118,121,2406,2698,4182,4946,153627, 3087192,8203485,38394376,487844934,2822741576, 4140154385,4397137572,8583966231] |