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| n | a(n) |
|---|---|
| 1 | 1229 |
| 2 | 3867 |
| 3 | 12387 |
| 4 | 39003 |
| 5 | 119359 |
| 6 | 357335 |
| 7 | 1052787 |
| 8 | 3069907 |
| 9 | 8903447 |
| 10 | 25780959 |
| 11 | 74735755 |
| 12 | 217269563 |
| 13 | 634036815 |
| 14 | 1857880039 |
| 15 | 5466025571 |
| 16 | 16140988131 |
| 17 | 47817974983 |
| 18 | 142048148015 |
| 19 | 422912961915 |
| 20 | 1261379418571 |
| 21 | 3767513043071 |
[1229,3867,12387,39003,119359,357335,1052787, 3069907,8903447,25780959,74735755,217269563, 634036815,1857880039,5466025571,16140988131, 47817974983,142048148015,422912961915, 1261379418571,3767513043071] |