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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 25 |
| 3 | 234 |
| 4 | 2305 |
| 5 | 23373 |
| 6 | 241486 |
| 7 | 2527920 |
| 8 | 26720529 |
| 9 | 284555700 |
| 10 | 3048323135 |
| 11 | 32812937820 |
| 12 | 354619072990 |
| 13 | 3845377105794 |
| 14 | 41817926091120 |
| 15 | 455893204069944 |
| 16 | 4980851709418353 |
| 17 | 54521955043418925 |
| 18 | 597823622561048020 |
| 19 | 6564929893462467450 |
| 20 | 72189820135528858455 |
[1,3,25,234,2305,23373,241486,2527920,26720529, 284555700,3048323135,32812937820,354619072990, 3845377105794,41817926091120,455893204069944, 4980851709418353,54521955043418925, 597823622561048020,6564929893462467450, 72189820135528858455] |