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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 18 |
| 2 | 299 |
| 3 | 4932 |
| 4 | 81301 |
| 5 | 1340118 |
| 6 | 22089599 |
| 7 | 364109832 |
| 8 | 6001737001 |
| 9 | 98928520218 |
| 10 | 1630669938899 |
| 11 | 26878845894732 |
| 12 | 443052477632701 |
| 13 | 7302973450020318 |
| 14 | 120377210159548199 |
| 15 | 1984215446621359632 |
| 16 | 32706447785195768401 |
| 17 | 539110673967989840418 |
| 18 | 8886330936793922917499 |
[1,18,299,4932,81301,1340118,22089599,364109832, 6001737001,98928520218,1630669938899, 26878845894732,443052477632701,7302973450020318, 120377210159548199,1984215446621359632, 32706447785195768401,539110673967989840418, 8886330936793922917499] |