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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 14 |
| 5 | 40 |
| 6 | 111 |
| 7 | 301 |
| 8 | 803 |
| 9 | 2118 |
| 10 | 5540 |
| 11 | 14397 |
| 12 | 37216 |
| 13 | 95772 |
| 14 | 245505 |
| 15 | 627189 |
| 16 | 1597413 |
| 17 | 4057450 |
| 18 | 10280678 |
| 19 | 25990933 |
| 20 | 65575122 |
| 21 | 165138416 |
| 22 | 415158963 |
| 23 | 1042067549 |
| 24 | 2611823431 |
| 25 | 6537384302 |
| 26 | 16342461128 |
| 27 | 40805714573 |
| 28 | 101776575332 |
| 29 | 253587643300 |
| 30 | 631232103045 |
[0,1,2,5,14,40,111,301,803,2118,5540,14397,37216, 95772,245505,627189,1597413,4057450,10280678, 25990933,65575122,165138416,415158963,1042067549, 2611823431,6537384302,16342461128,40805714573, 101776575332,253587643300,631232103045] |