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| n | a(n) |
|---|---|
| 2 | 1 |
| 3 | 2 |
| 4 | 10 |
| 5 | 40 |
| 6 | 187 |
| 7 | 854 |
| 8 | 4074 |
| 9 | 19602 |
| 10 | 96035 |
| 11 | 475492 |
| 12 | 2380042 |
| 13 | 12015368 |
| 14 | 61130186 |
| 15 | 313081232 |
| 16 | 1612967974 |
| 17 | 8353387992 |
| 18 | 43464071199 |
| 19 | 227101948596 |
| 20 | 1191127734498 |
| 21 | 6268882232536 |
| 22 | 33096647906860 |
| 23 | 175236408484988 |
| 24 | 930271133498794 |
| 25 | 4950509216635406 |
| 26 | 26403755607304762 |
| 27 | 141119182968584618 |
[1,2,10,40,187,854,4074,19602,96035,475492, 2380042,12015368,61130186,313081232,1612967974, 8353387992,43464071199,227101948596,1191127734498, 6268882232536,33096647906860,175236408484988, 930271133498794,4950509216635406, 26403755607304762,141119182968584618] |