The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 4 |
| 3 | 34 |
| 4 | 346 |
| 5 | 3965 |
| 6 | 48396 |
| 7 | 615966 |
| 8 | 8082457 |
| 9 | 108545916 |
| 10 | 1484716135 |
| 11 | 20612084010 |
| 12 | 289688970195 |
| 13 | 4113620233260 |
| 14 | 58930127470164 |
| 15 | 850641610106596 |
| 16 | 12360278974175769 |
| 17 | 180648953113093368 |
| 18 | 2653875476976308643 |
| 19 | 39167191622334514398 |
| 20 | 580439539153823110678 |
| 21 | 8633956582855204662785 |
[1,4,34,346,3965,48396,615966,8082457,108545916, 1484716135,20612084010,289688970195,4113620233260, 58930127470164,850641610106596,12360278974175769, 180648953113093368,2653875476976308643, 39167191622334514398,580439539153823110678, 8633956582855204662785] |