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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 24 |
| 3 | 255 |
| 4 | 3102 |
| 5 | 40854 |
| 6 | 566934 |
| 7 | 8164263 |
| 8 | 120864390 |
| 9 | 1827982362 |
| 10 | 28122626760 |
| 11 | 438720097638 |
| 12 | 6923868098820 |
| 13 | 110346550539780 |
| 14 | 1773394661610258 |
| 15 | 28707809007278775 |
| 16 | 467677404522668742 |
| 17 | 7661583171651546786 |
| 18 | 126137791939032756960 |
| 19 | 2085923447593966281378 |
[1,3,24,255,3102,40854,566934,8164263,120864390, 1827982362,28122626760,438720097638,6923868098820, 110346550539780,1773394661610258, 28707809007278775,467677404522668742, 7661583171651546786,126137791939032756960, 2085923447593966281378] |