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| n | a(n) |
|---|---|
| 4 | 1 |
| 5 | 16 |
| 6 | 181 |
| 7 | 1821 |
| 8 | 17557 |
| 9 | 167449 |
| 10 | 1604098 |
| 11 | 15555398 |
| 12 | 153315999 |
| 13 | 1538907306 |
| 14 | 15743413076 |
| 15 | 164161815768 |
| 16 | 1744049683213 |
| 17 | 18865209953045 |
| 18 | 207591285198178 |
| 19 | 2321616416280982 |
| 20 | 26362085777156567 |
| 21 | 303635722412859447 |
| 22 | 3544040394934246209 |
| 23 | 41881891423602685193 |
[1,16,181,1821,17557,167449,1604098,15555398, 153315999,1538907306,15743413076,164161815768, 1744049683213,18865209953045,207591285198178, 2321616416280982,26362085777156567, 303635722412859447,3544040394934246209, 41881891423602685193] |