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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 9 |
| 4 | 18 |
| 5 | 225 |
| 6 | 450 |
| 7 | 11025 |
| 8 | 22050 |
| 9 | 893025 |
| 10 | 1786050 |
| 11 | 108056025 |
| 12 | 216112050 |
| 13 | 18261468225 |
| 14 | 36522936450 |
| 15 | 4108830350625 |
| 16 | 8217660701250 |
| 17 | 1187451971330625 |
| 18 | 2374903942661250 |
| 19 | 428670161650355625 |
| 20 | 857340323300711250 |
| 21 | 189043541287806830625 |
| 22 | 378087082575613661250 |
[1,2,9,18,225,450,11025,22050,893025,1786050, 108056025,216112050,18261468225,36522936450, 4108830350625,8217660701250,1187451971330625, 2374903942661250,428670161650355625, 857340323300711250,189043541287806830625, 378087082575613661250] |