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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 4 |
| 3 | 14 |
| 4 | 44 |
| 5 | 130 |
| 6 | 496 |
| 7 | 1586 |
| 8 | 5128 |
| 9 | 17764 |
| 10 | 59492 |
| 11 | 196368 |
| 12 | 659330 |
| 13 | 2226166 |
| 14 | 7396070 |
| 15 | 24876724 |
| 16 | 83420692 |
| 17 | 279644938 |
| 18 | 935867180 |
| 19 | 3146178556 |
| 20 | 10534161782 |
| 21 | 35369902036 |
| 22 | 118498115768 |
| 23 | 398015733448 |
| 24 | 1333108657368 |
| 25 | 4477017033638 |
| 26 | 15004173961698 |
| 27 | 50369493608278 |
| 28 | 168842274387828 |
| 29 | 566766393991544 |
[1,1,4,14,44,130,496,1586,5128,17764,59492,196368, 659330,2226166,7396070,24876724,83420692, 279644938,935867180,3146178556,10534161782, 35369902036,118498115768,398015733448, 1333108657368,4477017033638,15004173961698, 50369493608278,168842274387828,566766393991544] |