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| n | a(n) |
|---|---|
| 1 | 4 |
| 2 | 16 |
| 3 | 64 |
| 4 | 225 |
| 5 | 841 |
| 6 | 3249 |
| 7 | 12996 |
| 8 | 51984 |
| 9 | 207936 |
| 10 | 829921 |
| 11 | 3316041 |
| 12 | 13256881 |
| 13 | 53027524 |
| 14 | 212110096 |
| 15 | 848440384 |
| 16 | 3393645025 |
| 17 | 13574347081 |
| 18 | 54296922289 |
| 19 | 217187689156 |
| 20 | 868750756624 |
| 21 | 3475003026496 |
| 22 | 13900004649441 |
| 23 | 55600003684681 |
[4,16,64,225,841,3249,12996,51984,207936,829921, 3316041,13256881,53027524,212110096,848440384, 3393645025,13574347081,54296922289,217187689156, 868750756624,3475003026496,13900004649441, 55600003684681] |