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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 3 |
| 4 | 10 |
| 5 | 53 |
| 6 | 304 |
| 7 | 2303 |
| 8 | 18768 |
| 9 | 185033 |
| 10 | 1954176 |
| 11 | 23756667 |
| 12 | 308077056 |
| 13 | 4457821821 |
| 14 | 68513332224 |
| 15 | 1150764459063 |
| 16 | 20443736745984 |
| 17 | 391167511473681 |
| 18 | 7884821722497024 |
| 19 | 169370797497060339 |
| 20 | 3818539009013907456 |
| 21 | 91013260219635394629 |
| 22 | 2269047587255097753600 |
| 23 | 59435772666287730632559 |
[1,1,3,10,53,304,2303,18768,185033,1954176, 23756667,308077056,4457821821,68513332224, 1150764459063,20443736745984,391167511473681, 7884821722497024,169370797497060339, 3818539009013907456,91013260219635394629, 2269047587255097753600,59435772666287730632559] |