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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 2 |
| 4 | 3 |
| 5 | 14 |
| 6 | 48 |
| 7 | 132 |
| 8 | 406 |
| 9 | 1430 |
| 10 | 4952 |
| 11 | 16796 |
| 12 | 58416 |
| 13 | 208012 |
| 14 | 744468 |
| 15 | 2674440 |
| 16 | 9688043 |
| 17 | 35357670 |
| 18 | 129674822 |
| 19 | 477638700 |
| 20 | 1767128768 |
| 21 | 6564120420 |
| 22 | 24466875156 |
| 23 | 91482563640 |
| 24 | 343056839170 |
| 25 | 1289904147324 |
| 26 | 4861959143296 |
| 27 | 18367353072152 |
| 28 | 69533492095732 |
| 29 | 263747951750360 |
[1,2,2,3,14,48,132,406,1430,4952,16796,58416, 208012,744468,2674440,9688043,35357670,129674822, 477638700,1767128768,6564120420,24466875156, 91482563640,343056839170,1289904147324, 4861959143296,18367353072152,69533492095732, 263747951750360] |