The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 3 |
| 4 | 11 |
| 5 | 44 |
| 6 | 193 |
| 7 | 882 |
| 8 | 4178 |
| 9 | 20305 |
| 10 | 100694 |
| 11 | 507493 |
| 12 | 2591897 |
| 13 | 13384911 |
| 14 | 69773480 |
| 15 | 366661360 |
| 16 | 1940336952 |
| 17 | 10331179153 |
| 18 | 55306072496 |
| 19 | 297499878304 |
| 20 | 1607212566176 |
| 21 | 8716586959731 |
| 22 | 47440220540922 |
| 23 | 259021671704538 |
| 24 | 1418386679682870 |
| 25 | 7787843448380598 |
| 26 | 42865830110488341 |
| 27 | 236480195092162079 |
[1,1,3,11,44,193,882,4178,20305,100694,507493, 2591897,13384911,69773480,366661360,1940336952, 10331179153,55306072496,297499878304, 1607212566176,8716586959731,47440220540922, 259021671704538,1418386679682870,7787843448380598, 42865830110488341,236480195092162079] |