The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 13 |
| 3 | 30 |
| 4 | 72 |
| 5 | 283 |
| 6 | 831 |
| 7 | 2399 |
| 8 | 7761 |
| 9 | 23840 |
| 10 | 72396 |
| 11 | 225569 |
| 12 | 696929 |
| 13 | 2144537 |
| 14 | 6635889 |
| 15 | 20510002 |
| 16 | 63318408 |
| 17 | 195704391 |
| 18 | 604826763 |
| 19 | 1868678179 |
| 20 | 5774848073 |
| 21 | 17846507936 |
| 22 | 55148861000 |
| 23 | 170427655945 |
| 24 | 526681961257 |
| 25 | 1627610746225 |
| 26 | 5029867948101 |
[1,13,30,72,283,831,2399,7761,23840,72396,225569, 696929,2144537,6635889,20510002,63318408, 195704391,604826763,1868678179,5774848073, 17846507936,55148861000,170427655945,526681961257, 1627610746225,5029867948101] |