The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 108 |
| 3 | 1650 |
| 4 | 15511 |
| 5 | 124030 |
| 6 | 887491 |
| 7 | 5870751 |
| 8 | 37029063 |
| 9 | 224989656 |
| 10 | 1329149598 |
| 11 | 7678897522 |
| 12 | 43562801122 |
| 13 | 243417797716 |
| 14 | 1342868232191 |
| 15 | 7327618165054 |
| 16 | 39607933952548 |
| 17 | 212329659406086 |
| 18 | 1129989079237450 |
| 19 | 5974847669219636 |
[0,108,1650,15511,124030,887491,5870751,37029063, 224989656,1329149598,7678897522,43562801122, 243417797716,1342868232191,7327618165054, 39607933952548,212329659406086,1129989079237450, 5974847669219636] |