The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 18 |
| 2 | 1104 |
| 3 | 57536 |
| 4 | 3079253 |
| 5 | 164206124 |
| 6 | 8761336545 |
| 7 | 467431319920 |
| 8 | 24938493433976 |
| 9 | 1330521524829842 |
| 10 | 70986162750517765 |
| 11 | 3787263138969145376 |
| 12 | 202058564666736227181 |
| 13 | 10780255299668629970930 |
| 14 | 575149608382918617117024 |
| 15 | 30685458073339150537724112 |
[1,18,1104,57536,3079253,164206124,8761336545, 467431319920,24938493433976,1330521524829842, 70986162750517765,3787263138969145376, 202058564666736227181,10780255299668629970930, 575149608382918617117024, 30685458073339150537724112] |