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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 20 |
| 3 | 972 |
| 4 | 90624 |
| 5 | 13828125 |
| 6 | 3133930176 |
| 7 | 988501957072 |
| 8 | 414139067400192 |
| 9 | 222497518123837665 |
| 10 | 149143419250000000000 |
| 11 | 122020951254446884154196 |
| 12 | 119671520043865789861724160 |
| 13 | 138593796657903100873209121453 |
[1,1,20,972,90624,13828125,3133930176, 988501957072,414139067400192,222497518123837665, 149143419250000000000,122020951254446884154196, 119671520043865789861724160, 138593796657903100873209121453] |