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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 24 |
| 5 | 120 |
| 6 | 577 |
| 7 | 2208 |
| 8 | 6768 |
| 9 | 17469 |
| 10 | 39603 |
| 11 | 81272 |
| 12 | 154225 |
| 13 | 274802 |
| 14 | 464985 |
| 15 | 753556 |
| 16 | 1177362 |
| 17 | 1782687 |
| 18 | 2626731 |
| 19 | 3779196 |
| 20 | 5323979 |
| 21 | 7360972 |
| 22 | 10007969 |
| 23 | 13402680 |
| 24 | 17704852 |
| 25 | 23098497 |
| 26 | 29794227 |
| 27 | 38031696 |
| 28 | 48082149 |
| 29 | 60251078 |
| 30 | 74880985 |
| 31 | 92354252 |
| 32 | 113096118 |
[1,2,6,24,120,577,2208,6768,17469,39603,81272, 154225,274802,464985,753556,1177362,1782687, 2626731,3779196,5323979,7360972,10007969,13402680, 17704852,23098497,29794227,38031696,48082149, 60251078,74880985,92354252,113096118] |