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| n | a(n) |
|---|---|
| 3 | 0 |
| 4 | 12 |
| 5 | 65 |
| 6 | 255 |
| 7 | 882 |
| 8 | 2870 |
| 9 | 9039 |
| 10 | 27945 |
| 11 | 85448 |
| 12 | 259512 |
| 13 | 784797 |
| 14 | 2366819 |
| 15 | 7125198 |
| 16 | 21424938 |
| 17 | 64373339 |
| 18 | 193316877 |
| 19 | 580344132 |
| 20 | 1741819148 |
| 21 | 5227030665 |
| 22 | 15684238119 |
| 23 | 47059006250 |
| 24 | 141189602142 |
| 25 | 423593972775 |
| 26 | 1270832250545 |
| 27 | 3812597415552 |
| 28 | 11437993573920 |
| 29 | 34314383375669 |
[0,12,65,255,882,2870,9039,27945,85448,259512, 784797,2366819,7125198,21424938,64373339, 193316877,580344132,1741819148,5227030665, 15684238119,47059006250,141189602142,423593972775, 1270832250545,3812597415552,11437993573920, 34314383375669] |