The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 22 |
| 5 | 86 |
| 6 | 358 |
| 7 | 1558 |
| 8 | 6966 |
| 9 | 31894 |
| 10 | 148918 |
| 11 | 705062 |
| 12 | 3380054 |
| 13 | 16381158 |
| 14 | 80056550 |
| 15 | 394266950 |
| 16 | 1955139942 |
| 17 | 9749771926 |
| 18 | 48873487942 |
| 19 | 246160229782 |
| 20 | 1244801094742 |
| 21 | 6318514387638 |
| 22 | 32184084454166 |
| 23 | 164425969781062 |
| 24 | 842429440124854 |
| 25 | 4327629345403078 |
| 26 | 22283328480744070 |
[1,2,6,22,86,358,1558,6966,31894,148918,705062, 3380054,16381158,80056550,394266950,1955139942, 9749771926,48873487942,246160229782,1244801094742, 6318514387638,32184084454166,164425969781062, 842429440124854,4327629345403078, 22283328480744070] |