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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 6 |
| 3 | 21 |
| 4 | 79 |
| 5 | 296 |
| 6 | 1117 |
| 7 | 4237 |
| 8 | 16147 |
| 9 | 61782 |
| 10 | 237208 |
| 11 | 913466 |
| 12 | 3526826 |
| 13 | 13647886 |
| 14 | 52920075 |
| 15 | 205566205 |
| 16 | 799791235 |
| 17 | 3116196550 |
| 18 | 12157265980 |
| 19 | 47485135510 |
| 20 | 185671296850 |
| 21 | 726703966600 |
| 22 | 2846827216330 |
| 23 | 11161555459090 |
| 24 | 43794648931054 |
[1,6,21,79,296,1117,4237,16147,61782,237208, 913466,3526826,13647886,52920075,205566205, 799791235,3116196550,12157265980,47485135510, 185671296850,726703966600,2846827216330, 11161555459090,43794648931054] |