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| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 14 |
| 3 | 128 |
| 4 | 1504 |
| 5 | 21752 |
| 6 | 374184 |
| 7 | 7464368 |
| 8 | 169402496 |
| 9 | 4309519952 |
| 10 | 121450640200 |
| 11 | 3755499322808 |
| 12 | 126409853754144 |
| 13 | 4600799868451880 |
| 14 | 180029930424249416 |
| 15 | 7536568838736534752 |
| 16 | 336087767194699956736 |
| 17 | 15905186914751401828640 |
| 18 | 796113699641442496367496 |
[2,14,128,1504,21752,374184,7464368,169402496, 4309519952,121450640200,3755499322808, 126409853754144,4600799868451880, 180029930424249416,7536568838736534752, 336087767194699956736,15905186914751401828640, 796113699641442496367496] |