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| n | a(n) |
|---|---|
| 3 | 0 |
| 4 | 0 |
| 5 | 4 |
| 6 | 6 |
| 7 | 8 |
| 8 | 22 |
| 9 | 60 |
| 10 | 102 |
| 11 | 262 |
| 12 | 694 |
| 13 | 1564 |
| 14 | 3552 |
| 15 | 9430 |
| 16 | 23423 |
| 17 | 57108 |
| 18 | 144774 |
| 19 | 374118 |
| 20 | 953824 |
| 21 | 2460356 |
| 22 | 6427240 |
| 23 | 16851190 |
| 24 | 44243785 |
| 25 | 117119492 |
| 26 | 311098391 |
| 27 | 828359180 |
| 28 | 2211105633 |
| 29 | 5921156854 |
| 30 | 15876753164 |
| 31 | 42641417130 |
[0,0,4,6,8,22,60,102,262,694,1564,3552,9430,23423, 57108,144774,374118,953824,2460356,6427240, 16851190,44243785,117119492,311098391,828359180, 2211105633,5921156854,15876753164,42641417130] |