The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 13 |
| 3 | 234 |
| 4 | 5566 |
| 5 | 165944 |
| 6 | 5966136 |
| 7 | 251491120 |
| 8 | 12169996912 |
| 9 | 665146831680 |
| 10 | 40530954643840 |
| 11 | 2724842629685120 |
| 12 | 200361647815660800 |
| 13 | 15997170878205905920 |
| 14 | 1378271357428552115200 |
| 15 | 127459020533529062246400 |
| 16 | 12593128815600367187507200 |
| 17 | 1323895109721239722075136000 |
[1,13,234,5566,165944,5966136,251491120, 12169996912,665146831680,40530954643840, 2724842629685120,200361647815660800, 15997170878205905920,1378271357428552115200, 127459020533529062246400, 12593128815600367187507200, 1323895109721239722075136000] |