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| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 12 |
| 3 | 136 |
| 4 | 1798 |
| 5 | 24472 |
| 6 | 334618 |
| 7 | 4578580 |
| 8 | 62655190 |
| 9 | 857412640 |
| 10 | 11733394642 |
| 11 | 160567489036 |
| 12 | 2197311225838 |
| 13 | 30069453572632 |
| 14 | 411490201499818 |
| 15 | 5631102858140740 |
| 16 | 77059719245016070 |
| 17 | 1054535937228511120 |
[2,12,136,1798,24472,334618,4578580,62655190, 857412640,11733394642,160567489036,2197311225838, 30069453572632,411490201499818,5631102858140740, 77059719245016070,1054535937228511120] |