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| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 14 |
| 3 | 38 |
| 4 | 97 |
| 5 | 245 |
| 6 | 631 |
| 7 | 1625 |
| 8 | 4234 |
| 9 | 11017 |
| 10 | 28652 |
| 11 | 74521 |
| 12 | 193836 |
| 13 | 504195 |
| 14 | 1311543 |
| 15 | 3411786 |
| 16 | 8875377 |
| 17 | 23088294 |
| 18 | 60062126 |
| 19 | 156247057 |
| 20 | 406466099 |
| 21 | 1057396975 |
| 22 | 2750760479 |
| 23 | 7155964344 |
| 24 | 18615901819 |
| 25 | 48428431650 |
| 26 | 125984478749 |
| 27 | 327743372244 |
[2,14,38,97,245,631,1625,4234,11017,28652,74521, 193836,504195,1311543,3411786,8875377,23088294, 60062126,156247057,406466099,1057396975, 2750760479,7155964344,18615901819,48428431650, 125984478749,327743372244] |