The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 6 |
| 3 | 105 |
| 4 | 3568 |
| 5 | 204745 |
| 6 | 18028266 |
| 7 | 2278860535 |
| 8 | 394667414016 |
| 9 | 90302033890953 |
| 10 | 26525942216131330 |
| 11 | 9775058594870836861 |
| 12 | 4433256936788979640848 |
| 13 | 2434899483389881601250937 |
| 14 | 1597444746833206096334387802 |
| 15 | 1237091666097626095124512681755 |
| 16 | 1119205949224015886848972396596736 |
[1,1,6,105,3568,204745,18028266,2278860535, 394667414016,90302033890953,26525942216131330, 9775058594870836861,4433256936788979640848, 2434899483389881601250937, 1597444746833206096334387802, 1237091666097626095124512681755, 1119205949224015886848972396596736] |