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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | 2 |
| 3 | 19 |
| 4 | 158 |
| 5 | 1825 |
| 6 | 24264 |
| 7 | 418343 |
| 8 | 8040802 |
| 9 | 186597501 |
| 10 | 5447823140 |
| 11 | 169904387719 |
| 12 | 6317118448398 |
| 13 | 260105476071197 |
[0,0,2,19,158,1825,24264,418343,8040802,186597501, 5447823140,169904387719,6317118448398, 260105476071197] |