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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 13 |
| 5 | 44 |
| 6 | 168 |
| 7 | 717 |
| 8 | 3359 |
| 9 | 17055 |
| 10 | 92749 |
| 11 | 534071 |
| 12 | 3220152 |
| 13 | 20122695 |
| 14 | 129180223 |
| 15 | 845868450 |
| 16 | 5618381653 |
| 17 | 37699577379 |
| 18 | 254789247816 |
| 19 | 1730682217663 |
| 20 | 11797467544723 |
| 21 | 80618379435810 |
| 22 | 551861368167305 |
| 23 | 3782253874750807 |
[1,2,5,13,44,168,717,3359,17055,92749,534071, 3220152,20122695,129180223,845868450,5618381653, 37699577379,254789247816,1730682217663, 11797467544723,80618379435810,551861368167305, 3782253874750807] |