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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 15 |
| 3 | 132 |
| 4 | 1565 |
| 5 | 22918 |
| 6 | 400939 |
| 7 | 8160008 |
| 8 | 189453369 |
| 9 | 4942271754 |
| 10 | 143128015943 |
| 11 | 4556517918604 |
| 12 | 158167223290453 |
| 13 | 5945611873120910 |
| 14 | 240619359452963427 |
| 15 | 10430922482219093520 |
| 16 | 482234053313600047217 |
| 17 | 23683786738296923795986 |
[1,2,15,132,1565,22918,400939,8160008,189453369, 4942271754,143128015943,4556517918604, 158167223290453,5945611873120910, 240619359452963427,10430922482219093520, 482234053313600047217,23683786738296923795986] |