The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 6 |
| 3 | 62 |
| 4 | 904 |
| 5 | 16984 |
| 6 | 390128 |
| 7 | 10586736 |
| 8 | 331267200 |
| 9 | 11738697600 |
| 10 | 464539452672 |
| 11 | 20302660659456 |
| 12 | 971106358760448 |
| 13 | 50452643588275200 |
| 14 | 2829000818124208128 |
| 15 | 170271405502300207104 |
| 16 | 10948525752699316371456 |
| 17 | 748994717201835804033024 |
| 18 | 54315931193865932254543872 |
[1,1,6,62,904,16984,390128,10586736,331267200, 11738697600,464539452672,20302660659456, 971106358760448,50452643588275200, 2829000818124208128,170271405502300207104, 10948525752699316371456,748994717201835804033024, 54315931193865932254543872] |