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| n | a(n) |
|---|---|
| 3 | 1 |
| 4 | 3 |
| 5 | 8 |
| 6 | 24 |
| 7 | 52 |
| 8 | 156 |
| 9 | 319 |
| 10 | 954 |
| 11 | 1910 |
| 12 | 5696 |
| 13 | 11304 |
| 14 | 33648 |
| 15 | 66514 |
| 16 | 197778 |
| 17 | 390266 |
| 18 | 1159844 |
| 19 | 2286996 |
| 20 | 6795576 |
| 21 | 13397075 |
| 22 | 39809076 |
| 23 | 78489235 |
| 24 | 233262931 |
| 25 | 460030947 |
| 26 | 1367463642 |
| 27 | 2697786052 |
| 28 | 8021305890 |
| 29 | 15830906756 |
| 30 | 47082494816 |
[1,3,8,24,52,156,319,954,1910,5696,11304,33648, 66514,197778,390266,1159844,2286996,6795576, 13397075,39809076,78489235,233262931,460030947, 1367463642,2697786052,8021305890,15830906756, 47082494816] |