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| n | a(n) |
|---|---|
| 3 | 0 |
| 4 | 2 |
| 5 | 2 |
| 6 | 4 |
| 7 | 14 |
| 8 | 30 |
| 9 | 46 |
| 10 | 141 |
| 11 | 321 |
| 12 | 648 |
| 13 | 1577 |
| 14 | 3589 |
| 15 | 7833 |
| 16 | 18573 |
| 17 | 43299 |
| 18 | 100786 |
| 19 | 244719 |
| 20 | 597693 |
| 21 | 1490664 |
| 22 | 3802784 |
| 23 | 9791113 |
| 24 | 25591883 |
| 25 | 67512476 |
| 26 | 178977181 |
| 27 | 476556092 |
| 28 | 1270559582 |
| 29 | 3386841730 |
| 30 | 9023105886 |
| 31 | 24004008044 |
[0,2,2,4,14,30,46,141,321,648,1577,3589,7833, 18573,43299,100786,244719,597693,1490664,3802784, 9791113,25591883,67512476,178977181,476556092, 1270559582,3386841730,9023105886,24004008044] |