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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 1 |
| 5 | 2 |
| 6 | 4 |
| 7 | 8 |
| 8 | 16 |
| 9 | 40 |
| 10 | 100 |
| 11 | 250 |
| 12 | 625 |
| 13 | 1875 |
| 14 | 5625 |
| 15 | 16875 |
| 16 | 50625 |
| 17 | 175500 |
| 18 | 608400 |
| 19 | 2109120 |
| 20 | 7311616 |
| 21 | 28543424 |
| 22 | 111429136 |
| 23 | 435002204 |
| 24 | 1698181681 |
| 25 | 7336479479 |
| 26 | 31695036961 |
| 27 | 136928804999 |
| 28 | 591559418641 |
| 29 | 2792538190620 |
| 30 | 13182563408400 |
| 31 | 62230116888000 |
[1,1,1,1,1,2,4,8,16,40,100,250,625,1875,5625, 16875,50625,175500,608400,2109120,7311616, 28543424,111429136,435002204,1698181681, 7336479479,31695036961,136928804999,591559418641, 2792538190620,13182563408400,62230116888000] |