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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 14 |
| 2 | 154 |
| 3 | 2688 |
| 4 | 34608 |
| 5 | 387744 |
| 6 | 4189920 |
| 7 | 42410496 |
| 8 | 408280992 |
| 9 | 3787340480 |
| 10 | 33960764992 |
| 11 | 295868561408 |
| 12 | 2514525570816 |
| 13 | 20906787095040 |
| 14 | 170489979041280 |
| 15 | 1366489403252736 |
| 16 | 10783773983748864 |
| 17 | 83916508450048512 |
| 18 | 644759749272120832 |
| 19 | 4896753272486297600 |
| 20 | 36796161089297096704 |
[1,14,154,2688,34608,387744,4189920,42410496, 408280992,3787340480,33960764992,295868561408, 2514525570816,20906787095040,170489979041280, 1366489403252736,10783773983748864, 83916508450048512,644759749272120832, 4896753272486297600,36796161089297096704] |