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| n | a(n) |
|---|---|
| 1 | 4 |
| 2 | 16 |
| 3 | 64 |
| 4 | 136 |
| 5 | 424 |
| 6 | 1216 |
| 7 | 2944 |
| 8 | 7696 |
| 9 | 24868 |
| 10 | 66016 |
| 11 | 187840 |
| 12 | 568864 |
| 13 | 1632232 |
| 14 | 4868992 |
| 15 | 14760064 |
| 16 | 43243552 |
| 17 | 129586312 |
| 18 | 390119248 |
| 19 | 1163757376 |
| 20 | 3491600176 |
| 21 | 10483526656 |
| 22 | 31391806528 |
| 23 | 94159476352 |
| 24 | 282588457024 |
| 25 | 847413793324 |
| 26 | 2541979556704 |
| 27 | 7627065915520 |
| 28 | 22877327084608 |
| 29 | 68630932189288 |
| 30 | 205904938577536 |
[4,16,64,136,424,1216,2944,7696,24868,66016, 187840,568864,1632232,4868992,14760064,43243552, 129586312,390119248,1163757376,3491600176, 10483526656,31391806528,94159476352,282588457024, 847413793324,2541979556704,7627065915520, 22877327084608,68630932189288,205904938577536] |