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| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 1 |
| 3 | 5 |
| 4 | 8 |
| 5 | 19 |
| 6 | 54 |
| 7 | 104 |
| 8 | 294 |
| 9 | 665 |
| 10 | 1653 |
| 11 | 3999 |
| 12 | 9931 |
| 13 | 23922 |
| 14 | 60440 |
| 15 | 145456 |
| 16 | 367778 |
| 17 | 895971 |
| 18 | 2252812 |
| 19 | 5539668 |
| 20 | 13906403 |
| 21 | 34364667 |
| 22 | 86296674 |
| 23 | 214005020 |
| 24 | 537481517 |
| 25 | 1337290024 |
| 26 | 3358607279 |
| 27 | 8379217095 |
| 28 | 21048882131 |
| 29 | 52624535726 |
| 30 | 132246784124 |
[2,1,5,8,19,54,104,294,665,1653,3999,9931,23922, 60440,145456,367778,895971,2252812,5539668, 13906403,34364667,86296674,214005020,537481517, 1337290024,3358607279,8379217095,21048882131, 52624535726,132246784124] |