The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 3 |
| 4 | 2 |
| 5 | 15 |
| 6 | 6 |
| 7 | 105 |
| 8 | 24 |
| 9 | 945 |
| 10 | 120 |
| 11 | 10395 |
| 12 | 720 |
| 13 | 135135 |
| 14 | 5040 |
| 15 | 2027025 |
| 16 | 40320 |
| 17 | 34459425 |
| 18 | 362880 |
| 19 | 654729075 |
| 20 | 3628800 |
| 21 | 13749310575 |
| 22 | 39916800 |
| 23 | 316234143225 |
| 24 | 479001600 |
| 25 | 7905853580625 |
| 26 | 6227020800 |
| 27 | 213458046676875 |
| 28 | 87178291200 |
| 29 | 6190283353629375 |
| 30 | 1307674368000 |
[1,1,1,3,2,15,6,105,24,945,120,10395,720,135135, 5040,2027025,40320,34459425,362880,654729075, 3628800,13749310575,39916800,316234143225, 479001600,7905853580625,6227020800, 213458046676875,87178291200,6190283353629375, 1307674368000] |