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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 4 |
| 3 | 41 |
| 4 | 979 |
| 5 | 40549 |
| 6 | 2571724 |
| 7 | 231313681 |
| 8 | 28007660854 |
| 9 | 4392400716381 |
| 10 | 866132386622878 |
| 11 | 209744116289535001 |
| 12 | 61192264076350570149 |
| 13 | 21169177815206345045941 |
| 14 | 8568352429497412897973944 |
| 15 | 4011525608882608159230362521 |
| 16 | 2151041235686896366408288920529 |
[1,1,4,41,979,40549,2571724,231313681,28007660854, 4392400716381,866132386622878,209744116289535001, 61192264076350570149,21169177815206345045941, 8568352429497412897973944, 4011525608882608159230362521, 2151041235686896366408288920529] |