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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 5 |
| 3 | 24 |
| 4 | 104 |
| 5 | 432 |
| 6 | 1736 |
| 7 | 6820 |
| 8 | 26332 |
| 9 | 100308 |
| 10 | 377996 |
| 11 | 1411844 |
| 12 | 5234428 |
| 13 | 19285252 |
| 14 | 70670972 |
| 15 | 257766212 |
| 16 | 936336572 |
| 17 | 3388962884 |
| 18 | 12226547132 |
| 19 | 43983439684 |
| 20 | 157814634684 |
| 21 | 564917186372 |
| 22 | 2017873643708 |
| 23 | 7193745818436 |
[0,1,5,24,104,432,1736,6820,26332,100308,377996, 1411844,5234428,19285252,70670972,257766212, 936336572,3388962884,12226547132,43983439684, 157814634684,564917186372,2017873643708, 7193745818436] |