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| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 1 |
| 3 | 2 |
| 4 | 3 |
| 5 | 6 |
| 6 | 10 |
| 7 | 22 |
| 8 | 42 |
| 9 | 94 |
| 10 | 203 |
| 11 | 470 |
| 12 | 1082 |
| 13 | 2602 |
| 14 | 6270 |
| 15 | 15482 |
| 16 | 38525 |
| 17 | 97258 |
| 18 | 247448 |
| 19 | 635910 |
| 20 | 1645411 |
| 21 | 4289010 |
| 22 | 11245670 |
| 23 | 29656148 |
| 24 | 78595028 |
| 25 | 209273780 |
| 26 | 559574414 |
| 27 | 1502130920 |
| 28 | 4046853091 |
| 29 | 10939133170 |
| 30 | 29661655793 |
[2,1,2,3,6,10,22,42,94,203,470,1082,2602,6270, 15482,38525,97258,247448,635910,1645411,4289010, 11245670,29656148,78595028,209273780,559574414, 1502130920,4046853091,10939133170,29661655793] |