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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 4 |
| 4 | 9 |
| 5 | 16 |
| 6 | 36 |
| 7 | 144 |
| 8 | 400 |
| 9 | 900 |
| 10 | 3600 |
| 11 | 11025 |
| 12 | 28224 |
| 13 | 78400 |
| 14 | 254016 |
| 15 | 705600 |
| 16 | 2286144 |
| 17 | 6350400 |
| 18 | 25401600 |
| 19 | 85377600 |
| 20 | 250905600 |
| 21 | 768398400 |
| 22 | 3073593600 |
| 23 | 10600761600 |
| 24 | 32464832400 |
| 25 | 129859329600 |
| 26 | 456536705625 |
[1,1,1,4,9,16,36,144,400,900,3600,11025,28224, 78400,254016,705600,2286144,6350400,25401600, 85377600,250905600,768398400,3073593600, 10600761600,32464832400,129859329600,456536705625] |