The OEIS is supported by the many generous donors to the OEIS Foundation.
Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.
Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 4 |
| 3 | 20 |
| 4 | 123 |
| 5 | 902 |
| 6 | 7656 |
| 7 | 73509 |
| 8 | 785154 |
| 9 | 9213324 |
| 10 | 117624569 |
| 11 | 1621028312 |
| 12 | 23959376436 |
| 13 | 377730250003 |
| 14 | 6322478398476 |
| 15 | 111904530008040 |
| 16 | 2087093471665987 |
| 17 | 40891426070289970 |
| 18 | 839329531471890724 |
| 19 | 18004595602417946685 |
| 20 | 402747680140030433886 |
| 21 | 9376084240910510840672 |
| 22 | 226760664399026618376569 |
[1,1,4,20,123,902,7656,73509,785154,9213324, 117624569,1621028312,23959376436,377730250003, 6322478398476,111904530008040,2087093471665987, 40891426070289970,839329531471890724, 18004595602417946685,402747680140030433886, 9376084240910510840672,226760664399026618376569] |