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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 10 |
| 4 | 43 |
| 5 | 206 |
| 6 | 1044 |
| 7 | 5909 |
| 8 | 38371 |
| 9 | 272314 |
| 10 | 1995208 |
| 11 | 14869889 |
| 12 | 115433344 |
| 13 | 965259881 |
| 14 | 8773348601 |
| 15 | 84608514095 |
| 16 | 837220780691 |
| 17 | 8334354200226 |
| 18 | 83498917650084 |
| 19 | 855936118936073 |
| 20 | 9180736840445788 |
| 21 | 104439240481045949 |
| 22 | 1253608634906635901 |
[1,1,3,10,43,206,1044,5909,38371,272314,1995208, 14869889,115433344,965259881,8773348601, 84608514095,837220780691,8334354200226, 83498917650084,855936118936073,9180736840445788, 104439240481045949,1253608634906635901] |