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| n | a(n) |
|---|---|
| 1 | 9 |
| 2 | 81 |
| 3 | 198 |
| 4 | 870 |
| 5 | 3358 |
| 6 | 12040 |
| 7 | 47320 |
| 8 | 182192 |
| 9 | 676396 |
| 10 | 2611234 |
| 11 | 9988846 |
| 12 | 37623896 |
| 13 | 144190134 |
| 14 | 550120868 |
| 15 | 2085006194 |
| 16 | 7964169488 |
| 17 | 30353664882 |
| 18 | 115358871282 |
| 19 | 439963965434 |
| 20 | 1676145338780 |
| 21 | 6377929104862 |
| 22 | 24307253165970 |
| 23 | 92589759354554 |
[9,81,198,870,3358,12040,47320,182192,676396, 2611234,9988846,37623896,144190134,550120868, 2085006194,7964169488,30353664882,115358871282, 439963965434,1676145338780,6377929104862, 24307253165970,92589759354554] |