The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 4 |
| 2 | 32 |
| 3 | 400 |
| 4 | 6800 |
| 5 | 146128 |
| 6 | 3795728 |
| 7 | 115616848 |
| 8 | 4040024720 |
| 9 | 159282704848 |
| 10 | 6993908053520 |
| 11 | 338443123424080 |
| 12 | 17894609985867152 |
| 13 | 1026351961130219728 |
| 14 | 63466858180767590672 |
| 15 | 4209071260503851502160 |
| 16 | 298006515851074633361552 |
| 17 | 22434758711582422326267856 |
[1,4,32,400,6800,146128,3795728,115616848, 4040024720,159282704848,6993908053520, 338443123424080,17894609985867152, 1026351961130219728,63466858180767590672, 4209071260503851502160,298006515851074633361552, 22434758711582422326267856] |