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| n | a(n) |
|---|---|
| 0 | 3 |
| 1 | 42 |
| 2 | 154 |
| 3 | 4620 |
| 4 | 87780 |
| 5 | 672980 |
| 6 | 18170460 |
| 7 | 1126568520 |
| 8 | 1126568520 |
| 9 | 14645390760 |
| 10 | 629751802680 |
| 11 | 29598334725960 |
| 12 | 503171690341320 |
| 13 | 100634338068264 |
| 14 | 29687129730137880 |
| 15 | 59374259460275760 |
| 16 | 3978075383838475920 |
| 17 | 282443352252531790320 |
| 18 | 1412216761262658951600 |
| 19 | 111565124139750057176400 |
| 20 | 9259905303599254745641200 |
[3,42,154,4620,87780,672980,18170460,1126568520, 1126568520,14645390760,629751802680, 29598334725960,503171690341320,100634338068264, 29687129730137880,59374259460275760, 3978075383838475920,282443352252531790320, 1412216761262658951600,111565124139750057176400, 9259905303599254745641200] |