The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 4 |
| 4 | 11 |
| 5 | 35 |
| 6 | 110 |
| 7 | 392 |
| 8 | 1372 |
| 9 | 4998 |
| 10 | 18251 |
| 11 | 67792 |
| 12 | 253043 |
| 13 | 952534 |
| 14 | 3602846 |
| 15 | 13699554 |
| 16 | 52298066 |
[1,1,4,11,35,110,392,1372,4998,18251,67792,253043, 952534,3602846,13699554,52298066] |