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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 1 |
| 3 | 4 |
| 4 | 9 |
| 5 | 28 |
| 6 | 73 |
| 7 | 144 |
| 8 | 409 |
| 9 | 1036 |
| 10 | 2025 |
| 11 | 5716 |
| 12 | 14449 |
| 13 | 28224 |
| 14 | 79633 |
| 15 | 201268 |
| 16 | 393129 |
| 17 | 1109164 |
| 18 | 2803321 |
| 19 | 5475600 |
| 20 | 15448681 |
| 21 | 39045244 |
| 22 | 76265289 |
| 23 | 215172388 |
| 24 | 543830113 |
| 25 | 1062238464 |
| 26 | 2996964769 |
| 27 | 7574576356 |
| 28 | 14795073225 |
| 29 | 41742334396 |
| 30 | 105500238889 |
| 31 | 206068786704 |
| 32 | 581395716793 |
| 33 | 1469428768108 |
[0,1,4,9,28,73,144,409,1036,2025,5716,14449,28224, 79633,201268,393129,1109164,2803321,5475600, 15448681,39045244,76265289,215172388,543830113, 1062238464,2996964769,7574576356,14795073225, 41742334396,105500238889,206068786704, 581395716793,1469428768108] |