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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | 1 |
| 3 | 3 |
| 4 | 11 |
| 5 | 35 |
| 6 | 115 |
| 7 | 371 |
| 8 | 1203 |
| 9 | 3891 |
| 10 | 12595 |
| 11 | 40755 |
| 12 | 131891 |
| 13 | 426803 |
| 14 | 1381171 |
| 15 | 4469555 |
| 16 | 14463795 |
| 17 | 46805811 |
| 18 | 151466803 |
| 19 | 490156851 |
| 20 | 1586180915 |
| 21 | 5132989235 |
| 22 | 16610702131 |
| 23 | 53753361203 |
| 24 | 173949530931 |
| 25 | 562912506675 |
| 26 | 1821623137075 |
| 27 | 5894896300851 |
| 28 | 19076285150003 |
[0,0,1,3,11,35,115,371,1203,3891,12595,40755, 131891,426803,1381171,4469555,14463795,46805811, 151466803,490156851,1586180915,5132989235, 16610702131,53753361203,173949530931,562912506675, 1821623137075,5894896300851,19076285150003] |