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| n | a(n) |
|---|---|
| 1 | 4 |
| 2 | 16 |
| 3 | 49 |
| 4 | 144 |
| 5 | 400 |
| 6 | 1089 |
| 7 | 2916 |
| 8 | 7744 |
| 9 | 20449 |
| 10 | 53824 |
| 11 | 141376 |
| 12 | 370881 |
| 13 | 972196 |
| 14 | 2547216 |
| 15 | 6671889 |
| 16 | 17472400 |
| 17 | 45751696 |
| 18 | 119793025 |
| 19 | 313644100 |
| 20 | 821166336 |
| 21 | 2149898689 |
| 22 | 5628600576 |
| 23 | 14736017664 |
| 24 | 38579637889 |
| 25 | 101003196100 |
| 26 | 264430435984 |
[4,16,49,144,400,1089,2916,7744,20449,53824, 141376,370881,972196,2547216,6671889,17472400, 45751696,119793025,313644100,821166336,2149898689, 5628600576,14736017664,38579637889,101003196100, 264430435984] |