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| n | a(n) |
|---|---|
| 1 | 9 |
| 2 | 81 |
| 3 | 171 |
| 4 | 361 |
| 5 | 1805 |
| 6 | 9025 |
| 7 | 25555 |
| 8 | 72361 |
| 9 | 292941 |
| 10 | 1185921 |
| 11 | 3801699 |
| 12 | 12187081 |
| 13 | 45351581 |
| 14 | 168766081 |
| 15 | 570110035 |
| 16 | 1925893225 |
| 17 | 6923341485 |
| 18 | 24888533121 |
| 19 | 85943617731 |
| 20 | 296775442441 |
| 21 | 1051712556989 |
| 22 | 3727058052481 |
| 23 | 12988702493491 |
[9,81,171,361,1805,9025,25555,72361,292941, 1185921,3801699,12187081,45351581,168766081, 570110035,1925893225,6923341485,24888533121, 85943617731,296775442441,1051712556989, 3727058052481,12988702493491] |