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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 30 |
| 2 | 464 |
| 3 | 4929 |
| 4 | 40424 |
| 5 | 272801 |
| 6 | 1576815 |
| 7 | 8023545 |
| 8 | 36665715 |
| 9 | 152763040 |
| 10 | 587171992 |
| 11 | 2101880476 |
| 12 | 7061614495 |
| 13 | 22410120565 |
| 14 | 67543053580 |
| 15 | 194231327451 |
| 16 | 535041945135 |
| 17 | 1416733053564 |
| 18 | 3616888634024 |
| 19 | 8926662604634 |
| 20 | 21349085390900 |
[1,30,464,4929,40424,272801,1576815,8023545, 36665715,152763040,587171992,2101880476, 7061614495,22410120565,67543053580,194231327451, 535041945135,1416733053564,3616888634024, 8926662604634,21349085390900] |