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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 14 |
| 5 | 44 |
| 6 | 144 |
| 7 | 487 |
| 8 | 1690 |
| 9 | 5968 |
| 10 | 21410 |
| 11 | 77778 |
| 12 | 285486 |
| 13 | 1057276 |
| 14 | 3944582 |
| 15 | 14810725 |
| 16 | 55915246 |
| 17 | 212094912 |
| 18 | 807838800 |
| 19 | 3088078508 |
| 20 | 11842326972 |
| 21 | 45542436464 |
| 22 | 175586377976 |
| 23 | 678496358882 |
| 24 | 2627165030106 |
| 25 | 10191179906996 |
| 26 | 39599018198800 |
| 27 | 154099574168302 |
| 28 | 600506786025438 |
| 29 | 2343056952632564 |
[1,1,2,5,14,44,144,487,1690,5968,21410,77778, 285486,1057276,3944582,14810725,55915246, 212094912,807838800,3088078508,11842326972, 45542436464,175586377976,678496358882, 2627165030106,10191179906996,39599018198800, 154099574168302,600506786025438,2343056952632564] |