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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 2 |
| 3 | 3 |
| 4 | 92 |
| 5 | 510 |
| 6 | 15114 |
| 7 | 174300 |
| 8 | 5558944 |
| 9 | 103712616 |
| 10 | 3672530280 |
| 11 | 96397602840 |
| 12 | 3830335035240 |
| 13 | 129817630491120 |
| 14 | 5796134828193696 |
| 15 | 239906921239210680 |
| 16 | 11996259216566469120 |
| 17 | 584024600798956215360 |
| 18 | 32523678395272329425856 |
[1,0,2,3,92,510,15114,174300,5558944,103712616, 3672530280,96397602840,3830335035240, 129817630491120,5796134828193696, 239906921239210680,11996259216566469120, 584024600798956215360,32523678395272329425856] |