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 | 12 |
| 4 | 42 |
| 5 | 156 |
| 6 | 606 |
| 7 | 2394 |
| 8 | 9804 |
| 9 | 40802 |
| 10 | 172286 |
| 11 | 738337 |
| 12 | 3202001 |
| 13 | 14007442 |
| 14 | 61830248 |
| 15 | 275035783 |
| 16 | 1231198753 |
| 17 | 5544051454 |
| 18 | 25101208259 |
| 19 | 114181560904 |
| 20 | 521629518564 |
| 21 | 2392582352822 |
| 22 | 11013730776909 |
| 23 | 50866209238898 |
| 24 | 235645872490463 |
| 25 | 1094762614098767 |
| 26 | 5099330548197097 |
| 27 | 23810432651755219 |
[1,1,4,12,42,156,606,2394,9804,40802,172286, 738337,3202001,14007442,61830248,275035783, 1231198753,5544051454,25101208259,114181560904, 521629518564,2392582352822,11013730776909, 50866209238898,235645872490463,1094762614098767, 5099330548197097,23810432651755219] |