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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 9 |
| 3 | 25 |
| 4 | 169 |
| 5 | 121 |
| 6 | 441 |
| 7 | 1521 |
| 8 | 2025 |
| 9 | 5625 |
| 10 | 24025 |
| 11 | 47089 |
| 12 | 109561 |
| 13 | 32761 |
| 14 | 393129 |
| 15 | 851929 |
| 16 | 1540081 |
| 17 | 6275025 |
| 18 | 15327225 |
| 19 | 27258841 |
| 20 | 41925625 |
| 21 | 127893481 |
| 22 | 243204025 |
| 23 | 385611769 |
| 24 | 998244025 |
| 25 | 1979449081 |
| 26 | 4823441401 |
| 27 | 12870221809 |
| 28 | 34324602361 |
[0,1,9,25,169,121,441,1521,2025,5625,24025,47089, 109561,32761,393129,851929,1540081,6275025, 15327225,27258841,41925625,127893481,243204025, 385611769,998244025,1979449081,4823441401, 12870221809,34324602361] |