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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 9 |
| 2 | 44 |
| 3 | 170 |
| 4 | 576 |
| 5 | 1792 |
| 6 | 5248 |
| 7 | 14688 |
| 8 | 39680 |
| 9 | 104192 |
| 10 | 267264 |
| 11 | 672256 |
| 12 | 1662976 |
| 13 | 4055040 |
| 14 | 9764864 |
| 15 | 23257088 |
| 16 | 54853632 |
| 17 | 128253952 |
| 18 | 297533440 |
| 19 | 685375488 |
| 20 | 1568669696 |
| 21 | 3569352704 |
| 22 | 8078229504 |
| 23 | 18192793600 |
| 24 | 40785412096 |
| 25 | 91049951232 |
[1,9,44,170,576,1792,5248,14688,39680,104192, 267264,672256,1662976,4055040,9764864,23257088, 54853632,128253952,297533440,685375488,1568669696, 3569352704,8078229504,18192793600,40785412096, 91049951232] |