The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 24 |
| 3 | 276 |
| 4 | 4086 |
| 5 | 73620 |
| 6 | 1557702 |
| 7 | 37770138 |
| 8 | 1030916484 |
| 9 | 31245154164 |
| 10 | 1040274476208 |
| 11 | 37716394860936 |
| 12 | 1478413316987424 |
| 13 | 62274364390387656 |
| 14 | 2804282634867538248 |
| 15 | 134397620584518275928 |
| 16 | 6828489621874434752208 |
| 17 | 366547074721109281366128 |
[1,3,24,276,4086,73620,1557702,37770138, 1030916484,31245154164,1040274476208, 37716394860936,1478413316987424,62274364390387656, 2804282634867538248,134397620584518275928, 6828489621874434752208,366547074721109281366128] |