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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 10 |
| 4 | 47 |
| 5 | 248 |
| 6 | 1354 |
| 7 | 7832 |
| 8 | 46672 |
| 9 | 285136 |
| 10 | 1775728 |
| 11 | 11232028 |
| 12 | 71959338 |
| 13 | 465981585 |
| 14 | 3045116666 |
| 15 | 20055877798 |
| 16 | 132995908915 |
| 17 | 887220714352 |
| 18 | 5950074234287 |
| 19 | 40092205226021 |
| 20 | 271289342487845 |
| 21 | 1842724189708458 |
| 22 | 12559944025175681 |
| 23 | 85877738644538351 |
[1,3,10,47,248,1354,7832,46672,285136,1775728, 11232028,71959338,465981585,3045116666, 20055877798,132995908915,887220714352, 5950074234287,40092205226021,271289342487845, 1842724189708458,12559944025175681, 85877738644538351] |