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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 6 |
| 2 | 39 |
| 3 | 224 |
| 4 | 1131 |
| 5 | 5412 |
| 6 | 24411 |
| 7 | 105078 |
| 8 | 435048 |
| 9 | 1740312 |
| 10 | 6755877 |
| 11 | 25533330 |
| 12 | 94205738 |
| 13 | 340064322 |
| 14 | 1203313782 |
| 15 | 4180514846 |
| 16 | 14279610417 |
| 17 | 48013553310 |
| 18 | 159086287869 |
| 19 | 519912616614 |
| 20 | 1677331973910 |
| 21 | 5345927500226 |
| 22 | 16843574682291 |
| 23 | 52494817082952 |
| 24 | 161923200857711 |
[1,6,39,224,1131,5412,24411,105078,435048,1740312, 6755877,25533330,94205738,340064322,1203313782, 4180514846,14279610417,48013553310,159086287869, 519912616614,1677331973910,5345927500226, 16843574682291,52494817082952,161923200857711] |