The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 66 |
| 5 | 946 |
| 6 | 8646 |
| 7 | 180246 |
| 8 | 199606 |
| 9 | 265826 |
| 10 | 383846 |
| 11 | 1234806 |
| 12 | 3757426 |
| 13 | 9880278 |
| 14 | 14304466 |
| 15 | 23612226 |
| 16 | 27052806 |
| 17 | 43091686 |
| 18 | 63265474 |
| 19 | 66154726 |
| 20 | 69410706 |
| 21 | 81517766 |
| 22 | 106047766 |
| 23 | 129773526 |
| 24 | 130520566 |
| 25 | 149497986 |
| 26 | 184416166 |
| 27 | 279383126 |
[1,2,6,66,946,8646,180246,199606,265826,383846, 1234806,3757426,9880278,14304466,23612226, 27052806,43091686,63265474,66154726,69410706, 81517766,106047766,129773526,130520566,149497986, 184416166,279383126] |