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| n | a(n) |
|---|---|
| 4 | 2 |
| 5 | 13 |
| 6 | 61 |
| 7 | 248 |
| 8 | 935 |
| 9 | 3368 |
| 10 | 11777 |
| 11 | 40347 |
| 12 | 136214 |
| 13 | 454922 |
| 14 | 1507000 |
| 15 | 4961100 |
| 16 | 16253188 |
| 17 | 53045703 |
| 18 | 172607505 |
| 19 | 560317916 |
| 20 | 1815445901 |
| 21 | 5873136282 |
| 22 | 18976870985 |
| 23 | 61256217631 |
| 24 | 197573796328 |
| 25 | 636837047532 |
| 26 | 2051636248268 |
| 27 | 6606758265032 |
| 28 | 21268025275930 |
| 29 | 68445465415825 |
[2,13,61,248,935,3368,11777,40347,136214,454922, 1507000,4961100,16253188,53045703,172607505, 560317916,1815445901,5873136282,18976870985, 61256217631,197573796328,636837047532, 2051636248268,6606758265032,21268025275930, 68445465415825] |