The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 312 |
| 2 | 18642 |
| 3 | 447096 |
| 4 | 6004674 |
| 5 | 53600248 |
| 6 | 353024594 |
| 7 | 1839267768 |
| 8 | 7960151810 |
| 9 | 29653889720 |
| 10 | 97649896786 |
| 11 | 290078713080 |
| 12 | 789747027394 |
| 13 | 1995416563064 |
| 14 | 4726400795090 |
| 15 | 10581459177016 |
| 16 | 22543374588930 |
| 17 | 45962181162040 |
| 18 | 90105620342738 |
| 19 | 170538349148024 |
| 20 | 312685497919938 |
[1,312,18642,447096,6004674,53600248,353024594, 1839267768,7960151810,29653889720,97649896786, 290078713080,789747027394,1995416563064, 4726400795090,10581459177016,22543374588930, 45962181162040,90105620342738,170538349148024, 312685497919938] |