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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 6 |
| 3 | 32 |
| 4 | 242 |
| 5 | 2472 |
| 6 | 31850 |
| 7 | 490912 |
| 8 | 8897058 |
| 9 | 185373722 |
| 10 | 4344896842 |
| 11 | 113667973344 |
| 12 | 3283155709106 |
| 13 | 103486639506824 |
| 14 | 3544144942010010 |
| 15 | 131038318999642112 |
| 16 | 5192873357864667202 |
| 17 | 219952910549005233840 |
| 18 | 9916266932124308092586 |
| 19 | 473513072853351852164160 |
[1,2,6,32,242,2472,31850,490912,8897058,185373722, 4344896842,113667973344,3283155709106, 103486639506824,3544144942010010, 131038318999642112,5192873357864667202, 219952910549005233840,9916266932124308092586, 473513072853351852164160] |