The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 57 |
| 3 | 4172 |
| 4 | 15508 |
| 5 | 50510 |
| 6 | 119319 |
| 7 | 243040 |
| 8 | 458646 |
| 9 | 836348 |
| 10 | 1499031 |
| 11 | 2639156 |
| 12 | 4598088 |
| 13 | 7964505 |
| 14 | 13723351 |
| 15 | 23542072 |
| 16 | 40224454 |
| 17 | 68484867 |
| 18 | 116236613 |
| 19 | 196696242 |
| 20 | 331912800 |
| 21 | 558609817 |
| 22 | 937824339 |
| 23 | 1570843506 |
| 24 | 2625457910 |
| 25 | 4379204675 |
[0,57,4172,15508,50510,119319,243040,458646, 836348,1499031,2639156,4598088,7964505,13723351, 23542072,40224454,68484867,116236613,196696242, 331912800,558609817,937824339,1570843506, 2625457910,4379204675] |