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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 12 |
| 4 | 200 |
| 5 | 4160 |
| 6 | 99862 |
| 7 | 2767792 |
| 8 | 87200166 |
| 9 | 3076185774 |
| 10 | 120118928740 |
| 11 | 5144915483804 |
| 12 | 239932734849080 |
| 13 | 12106729328331780 |
| 14 | 657428964058944716 |
| 15 | 38239094075667233528 |
| 16 | 2372421500769940561658 |
| 17 | 156417910715313378830238 |
| 18 | 10923007991339600108590688 |
| 19 | 805475337677577620666606928 |
| 20 | 62550798567594006106067173708 |
[1,1,2,12,200,4160,99862,2767792,87200166, 3076185774,120118928740,5144915483804, 239932734849080,12106729328331780, 657428964058944716,38239094075667233528, 2372421500769940561658,156417910715313378830238, 10923007991339600108590688, 805475337677577620666606928, 62550798567594006106067173708] |