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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 9 |
| 4 | 36 |
| 5 | 225 |
| 6 | 1350 |
| 7 | 11025 |
| 8 | 88200 |
| 9 | 893025 |
| 10 | 8930250 |
| 11 | 108056025 |
| 12 | 1296672300 |
| 13 | 18261468225 |
| 14 | 255660555150 |
| 15 | 4108830350625 |
| 16 | 65741285610000 |
| 17 | 1187451971330625 |
| 18 | 21374135483951250 |
| 19 | 428670161650355625 |
| 20 | 8573403233007112500 |
[1,2,9,36,225,1350,11025,88200,893025,8930250, 108056025,1296672300,18261468225,255660555150, 4108830350625,65741285610000,1187451971330625, 21374135483951250,428670161650355625, 8573403233007112500] |