The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 4 |
| 3 | 20 |
| 4 | 31 |
| 5 | 14564 |
| 6 | 38239 |
| 7 | 69919 |
| 8 | 120395 |
| 9 | 426436 |
| 10 | 902596 |
| 11 | 7478020 |
| 12 | 9090220 |
| 13 | 6671332084 |
| 14 | 8114264059 |
| 15 | 8482227259 |
| 16 | 9900250996 |
| 17 | 2244338786836 |
| 18 | 2490577152964 |
| 19 | 2509440638591 |
| 20 | 2769448208395 |
| 21 | 7012067592220 |
[1,4,20,31,14564,38239,69919,120395,426436,902596, 7478020,9090220,6671332084,8114264059,8482227259, 9900250996,2244338786836,2490577152964, 2509440638591,2769448208395,7012067592220] |