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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 4 |
| 4 | 13 |
| 5 | 38 |
| 6 | 133 |
| 7 | 472 |
| 8 | 1765 |
| 9 | 6824 |
| 10 | 27021 |
| 11 | 109776 |
| 12 | 454221 |
| 13 | 1910817 |
| 14 | 8155244 |
| 15 | 35228927 |
| 16 | 153824125 |
| 17 | 678070366 |
| 18 | 3013894753 |
| 19 | 13496603167 |
| 20 | 60844279321 |
| 21 | 275940416256 |
| 22 | 1258264355646 |
| 23 | 5765883287937 |
| 24 | 26540341660458 |
| 25 | 122667242961872 |
| 26 | 569091334275080 |
| 27 | 2649328455973642 |
| 28 | 12372953219581326 |
[1,1,2,4,13,38,133,472,1765,6824,27021,109776, 454221,1910817,8155244,35228927,153824125, 678070366,3013894753,13496603167,60844279321, 275940416256,1258264355646,5765883287937, 26540341660458,122667242961872,569091334275080, 2649328455973642,12372953219581326] |