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| n | a(n) |
|---|---|
| 8 | 1 |
| 9 | 18 |
| 10 | 360 |
| 11 | 7260 |
| 12 | 152460 |
| 13 | 3361644 |
| 14 | 78041964 |
| 15 | 1908389340 |
| 16 | 49118959890 |
| 17 | 1328964080730 |
| 18 | 37738620245898 |
| 19 | 1122927974067042 |
| 20 | 34953464391146730 |
| 21 | 1136306352798186570 |
| 22 | 38520124906043253330 |
| 23 | 1359621561034260858906 |
| 24 | 49896547074800880656202 |
| 25 | 1901350452285623246965200 |
[1,18,360,7260,152460,3361644,78041964,1908389340, 49118959890,1328964080730,37738620245898, 1122927974067042,34953464391146730, 1136306352798186570,38520124906043253330, 1359621561034260858906,49896547074800880656202, 1901350452285623246965200] |