| n | a(n) |
|---|---|
| 1 | 4 |
| 2 | 9 |
| 3 | 16 |
| 4 | 64 |
| 5 | 196 |
| 6 | 1296 |
| 7 | 3600 |
| 8 | 35344 |
| 9 | 1397124 |
| 10 | 4804864 |
| 11 | 213218404 |
| 12 | 2754990144 |
| 13 | 9976014400 |
| 14 | 133023596176 |
| 15 | 6663770519184 |
| 16 | 342723467635264 |
| 17 | 1281107924034624 |
| 18 | 67756702226982976 |
| 19 | 963748303995476224 |
| 20 | 3643830108147610000 |
| 21 | 198705767966065582336 |
| 22 | 2876682497805092456704 |
[4,9,16,64,196,1296,3600,35344,1397124,4804864, 213218404,2754990144,9976014400,133023596176, 6663770519184,342723467635264,1281107924034624, 67756702226982976,963748303995476224, 3643830108147610000,198705767966065582336, 2876682497805092456704] |