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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 2 |
| 3 | 9 |
| 4 | 28 |
| 5 | 125 |
| 6 | 486 |
| 7 | 2317 |
| 8 | 10424 |
| 9 | 53433 |
| 10 | 267850 |
| 11 | 1470161 |
| 12 | 8032212 |
| 13 | 46925749 |
| 14 | 275437358 |
| 15 | 1702883925 |
| 16 | 10630404976 |
| 17 | 69192858737 |
| 18 | 455957606034 |
| 19 | 3110617216153 |
| 20 | 21512638153100 |
| 21 | 153234193139181 |
| 22 | 1107087138215542 |
| 23 | 8206182165264029 |
| 24 | 61703155328534568 |
[0,1,2,9,28,125,486,2317,10424,53433,267850, 1470161,8032212,46925749,275437358,1702883925, 10630404976,69192858737,455957606034, 3110617216153,21512638153100,153234193139181, 1107087138215542,8206182165264029, 61703155328534568] |