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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 6 |
| 3 | 32 |
| 4 | 108 |
| 5 | 384 |
| 6 | 2688 |
| 7 | 5632 |
| 8 | 27864 |
| 9 | 153920 |
| 10 | 499968 |
| 11 | 1477440 |
| 12 | 11708928 |
| 13 | 22380544 |
| 14 | 115568640 |
| 15 | 620101632 |
| 16 | 1826150832 |
| 17 | 5726797824 |
| 18 | 54044390400 |
| 19 | 91626668032 |
| 20 | 555102471168 |
| 21 | 2352412508160 |
| 22 | 7458459886080 |
| 23 | 23955459951744 |
| 24 | 199536712962048 |
| 25 | 425355918188544 |
| 26 | 1849167560835072 |
[1,6,32,108,384,2688,5632,27864,153920,499968, 1477440,11708928,22380544,115568640,620101632, 1826150832,5726797824,54044390400,91626668032, 555102471168,2352412508160,7458459886080, 23955459951744,199536712962048,425355918188544, 1849167560835072] |