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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 4 |
| 3 | 64 |
| 4 | 7132 |
| 5 | 201538000 |
| 6 | 432345572694417712 |
| 7 | 3987683987354747642922773353963277968 |
| 8 | 678469272874899582559986240285280710364867063489779510427038722229750276832 |
[1,1,4,64,7132,201538000,432345572694417712, 3987683987354747642922773353963277968, 67846927287489958255998624028528071036486706348977\ 9510427038722229750276832] |