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| n | a(n) |
|---|---|
| 7 | 1 |
| 8 | 8 |
| 9 | 72 |
| 10 | 600 |
| 11 | 4950 |
| 12 | 41184 |
| 13 | 348348 |
| 14 | 3008148 |
| 15 | 26608725 |
| 16 | 241395440 |
| 17 | 2247683152 |
| 18 | 21485909952 |
| 19 | 210840271980 |
| 20 | 2123351405280 |
| 21 | 21937875152760 |
| 22 | 232419281905272 |
| 23 | 2523691371079725 |
| 24 | 28070949453307992 |
| 25 | 319668800125675000 |
| 26 | 3725037254807468600 |
| 27 | 44393091629344788330 |
[1,8,72,600,4950,41184,348348,3008148,26608725, 241395440,2247683152,21485909952,210840271980, 2123351405280,21937875152760,232419281905272, 2523691371079725,28070949453307992, 319668800125675000,3725037254807468600, 44393091629344788330] |