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| n | a(n) |
|---|---|
| 1 | 12 |
| 2 | 80 |
| 3 | 624 |
| 4 | 3760 |
| 5 | 25002 |
| 6 | 171068 |
| 7 | 1107888 |
| 8 | 7411872 |
| 9 | 50469114 |
| 10 | 335270710 |
| 11 | 2266967088 |
| 12 | 15497479060 |
| 13 | 104719636176 |
| 14 | 715192200880 |
| 15 | 4919017621164 |
| 16 | 33647413101184 |
| 17 | 231673960276602 |
| 18 | 1602349695229334 |
| 19 | 11054192845643568 |
[12,80,624,3760,25002,171068,1107888,7411872, 50469114,335270710,2266967088,15497479060, 104719636176,715192200880,4919017621164, 33647413101184,231673960276602,1602349695229334, 11054192845643568] |