The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 5 |
| 3 | 381 |
| 4 | 1810 |
| 5 | 137561 |
| 6 | 653415 |
| 7 | 49659541 |
| 8 | 235882820 |
| 9 | 17927094321 |
| 10 | 85153698025 |
| 11 | 6471681049901 |
| 12 | 30740484987030 |
| 13 | 2336276859014281 |
| 14 | 11097315080317835 |
| 15 | 843395946104155461 |
| 16 | 4006130743994738440 |
[0,1,5,381,1810,137561,653415,49659541,235882820, 17927094321,85153698025,6471681049901, 30740484987030,2336276859014281,11097315080317835, 843395946104155461,4006130743994738440] |