The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 0 |
| 3 | 2 |
| 4 | 24 |
| 5 | 572 |
| 6 | 21280 |
| 7 | 1074390 |
| 8 | 70299264 |
| 9 | 5792903144 |
| 10 | 587159944704 |
| 11 | 71822748886440 |
| 12 | 10435273503677440 |
| 13 | 1776780701352504408 |
| 14 | 350461958856515690496 |
| 15 | 79284041282799128098778 |
| 16 | 20392765404792755583221760 |
| 17 | 5917934230798152486136427600 |
| 18 | 1924427226324694427836833857536 |
[1,0,0,2,24,572,21280,1074390,70299264,5792903144, 587159944704,71822748886440,10435273503677440, 1776780701352504408,350461958856515690496, 79284041282799128098778, 20392765404792755583221760, 5917934230798152486136427600, 1924427226324694427836833857536] |