The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 7 |
| 3 | 24 |
| 4 | 101 |
| 5 | 392 |
| 6 | 1703 |
| 7 | 7119 |
| 8 | 31486 |
| 9 | 135870 |
| 10 | 610317 |
| 11 | 2689175 |
| 12 | 12179773 |
| 13 | 54466446 |
| 14 | 248384257 |
| 15 | 1121795909 |
| 16 | 5143391889 |
| 17 | 23410157731 |
| 18 | 107778940707 |
| 19 | 493502891246 |
| 20 | 2280127647681 |
| 21 | 10490012968322 |
| 22 | 48610428832274 |
| 23 | 224519830847282 |
| 24 | 1043056422167442 |
| 25 | 4833374956628301 |
| 26 | 22504407440499129 |
| 27 | 104571539083591522 |
[1,2,7,24,101,392,1703,7119,31486,135870,610317, 2689175,12179773,54466446,248384257,1121795909, 5143391889,23410157731,107778940707,493502891246, 2280127647681,10490012968322,48610428832274, 224519830847282,1043056422167442,4833374956628301, 22504407440499129,104571539083591522] |