The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 1 |
| 5 | 1 |
| 6 | 1 |
| 7 | 5 |
| 8 | 13 |
| 9 | 25 |
| 10 | 57 |
| 11 | 197 |
| 12 | 913 |
| 13 | 4565 |
| 14 | 21033 |
| 15 | 117411 |
| 16 | 799889 |
| 17 | 6782571 |
| 18 | 62778947 |
| 19 | 652383615 |
| 20 | 7631737235 |
| 21 | 109519353841 |
| 22 | 1777185991253 |
| 23 | 33840206146839 |
| 24 | 713322877970345 |
| 25 | 17898267949061373 |
| 26 | 507994433535644661 |
[1,1,1,1,1,1,5,13,25,57,197,913,4565,21033,117411, 799889,6782571,62778947,652383615,7631737235, 109519353841,1777185991253,33840206146839, 713322877970345,17898267949061373, 507994433535644661] |