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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 2 |
| 3 | 18 |
| 4 | 302 |
| 5 | 7770 |
| 6 | 285182 |
| 7 | 14169498 |
| 8 | 916379102 |
| 9 | 74833699770 |
| 10 | 7532323742462 |
| 11 | 916288114073178 |
| 12 | 132533661862902302 |
| 13 | 22482642651307262970 |
| 14 | 4420834602574484743742 |
| 15 | 997471931914411955132058 |
| 16 | 255978001773528747607767902 |
| 17 | 74137405656663750753878861370 |
[1,0,2,18,302,7770,285182,14169498,916379102, 74833699770,7532323742462,916288114073178, 132533661862902302,22482642651307262970, 4420834602574484743742,997471931914411955132058, 255978001773528747607767902, 74137405656663750753878861370] |