The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 14 |
| 3 | 63 |
| 4 | 287 |
| 5 | 1306 |
| 6 | 5945 |
| 7 | 27061 |
| 8 | 123180 |
| 9 | 560707 |
| 10 | 2552301 |
| 11 | 11617904 |
| 12 | 52883925 |
| 13 | 240724103 |
| 14 | 1095760078 |
| 15 | 4987826867 |
| 16 | 22704255571 |
| 17 | 103348258626 |
| 18 | 470434387405 |
| 19 | 2141385987489 |
| 20 | 9747446339348 |
| 21 | 44369726286423 |
| 22 | 201968037801353 |
[1,3,14,63,287,1306,5945,27061,123180,560707, 2552301,11617904,52883925,240724103,1095760078, 4987826867,22704255571,103348258626,470434387405, 2141385987489,9747446339348,44369726286423, 201968037801353] |