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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 13 |
| 3 | 39 |
| 4 | 202 |
| 5 | 894 |
| 6 | 4507 |
| 7 | 22684 |
| 8 | 116651 |
| 9 | 605727 |
| 10 | 3159382 |
| 11 | 16537678 |
| 12 | 86697810 |
| 13 | 454970673 |
| 14 | 2388855177 |
| 15 | 12546612125 |
| 16 | 65907887547 |
| 17 | 346249228930 |
| 18 | 1819128113520 |
| 19 | 9557636406332 |
| 20 | 50216318435526 |
| 21 | 263841572707504 |
| 22 | 1386257187235490 |
[1,13,39,202,894,4507,22684,116651,605727,3159382, 16537678,86697810,454970673,2388855177, 12546612125,65907887547,346249228930, 1819128113520,9557636406332,50216318435526, 263841572707504,1386257187235490] |