The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 1620 |
| 3 | 46872 |
| 4 | 1104264 |
| 5 | 23549400 |
| 6 | 474819408 |
| 7 | 9230973192 |
| 8 | 174918307032 |
| 9 | 3252108138552 |
| 10 | 59583135523968 |
| 11 | 1078987217468328 |
| 12 | 19354648265646120 |
| 13 | 344454190256524824 |
| 14 | 6089633274402902448 |
| 15 | 107049250394211722184 |
[0,1620,46872,1104264,23549400,474819408, 9230973192,174918307032,3252108138552, 59583135523968,1078987217468328,19354648265646120, 344454190256524824,6089633274402902448, 107049250394211722184] |