The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 7 |
| 3 | 25 |
| 4 | 102 |
| 5 | 403 |
| 6 | 1737 |
| 7 | 7244 |
| 8 | 31911 |
| 9 | 137926 |
| 10 | 615976 |
| 11 | 2717221 |
| 12 | 12268696 |
| 13 | 54843343 |
| 14 | 249585694 |
| 15 | 1127105125 |
| 16 | 5158721778 |
| 17 | 23478404133 |
| 18 | 107958051841 |
| 19 | 494269144847 |
| 20 | 2281524240969 |
| 21 | 10495551496764 |
| 22 | 48601873781132 |
| 23 | 224465125580471 |
| 24 | 1042241504635216 |
| 25 | 4829414998947986 |
| 26 | 22476564935460318 |
| 27 | 104439565069138006 |
[1,2,7,25,102,403,1737,7244,31911,137926,615976, 2717221,12268696,54843343,249585694,1127105125, 5158721778,23478404133,107958051841,494269144847, 2281524240969,10495551496764,48601873781132, 224465125580471,1042241504635216,4829414998947986, 22476564935460318,104439565069138006] |