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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 11 |
| 3 | 122 |
| 4 | 1353 |
| 5 | 15005 |
| 6 | 166408 |
| 7 | 1845493 |
| 8 | 20466831 |
| 9 | 226980634 |
| 10 | 2517253805 |
| 11 | 27916772489 |
| 12 | 309601751184 |
| 13 | 3433536035513 |
| 14 | 38078498141827 |
| 15 | 422297015595610 |
| 16 | 4683345669693537 |
| 17 | 51939099382224517 |
| 18 | 576013438874163224 |
[0,1,11,122,1353,15005,166408,1845493,20466831, 226980634,2517253805,27916772489,309601751184, 3433536035513,38078498141827,422297015595610, 4683345669693537,51939099382224517, 576013438874163224] |