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| n | a(n) |
|---|---|
| 1 | 3 |
| 2 | 31 |
| 3 | 258 |
| 4 | 2241 |
| 5 | 19408 |
| 6 | 167960 |
| 7 | 1453952 |
| 8 | 12585637 |
| 9 | 108943526 |
| 10 | 943035150 |
| 11 | 8163084148 |
| 12 | 70661144632 |
| 13 | 611655753520 |
| 14 | 5294603734144 |
| 15 | 45831055372945 |
| 16 | 396721972412987 |
| 17 | 3434097733826959 |
| 18 | 29726176177614458 |
| 19 | 257315201439500033 |
[3,31,258,2241,19408,167960,1453952,12585637, 108943526,943035150,8163084148,70661144632, 611655753520,5294603734144,45831055372945, 396721972412987,3434097733826959, 29726176177614458,257315201439500033] |