The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 3 |
| 5 | 3 |
| 6 | 5 |
| 7 | 9 |
| 8 | 17 |
| 9 | 89 |
| 10 | 140 |
| 11 | 1134 |
| 12 | 2523 |
| 13 | 20495 |
| 14 | 73514 |
| 15 | 534008 |
| 16 | 1996987 |
| 17 | 23508472 |
| 18 | 92663083 |
| 19 | 1862869380 |
| 20 | 7762461636 |
| 21 | 266742576438 |
| 22 | 1312733745392 |
| 23 | 59491047519251 |
| 24 | 367850100364195 |
| 25 | 19425750984998415 |
| 26 | 144916187683650857 |
[1,1,1,3,3,5,9,17,89,140,1134,2523,20495,73514, 534008,1996987,23508472,92663083,1862869380, 7762461636,266742576438,1312733745392, 59491047519251,367850100364195,19425750984998415, 144916187683650857] |