| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 2009078326886400 |
| 4 | 25130033447370922318407480728239472640000000 |
| 5 | 5759627596191312699511553760965199283079808523515804251057792885981184000000000000000 |
[1,1,2009078326886400, 25130033447370922318407480728239472640000000, 57596275961913126995115537609651992830798085235158\ 04251057792885981184000000000000000] |