| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 5 |
| 3 | 24 |
| 4 | 116 |
| 5 | 568 |
| 6 | 2820 |
| 7 | 14184 |
| 8 | 72180 |
| 9 | 371112 |
| 10 | 1925380 |
| 11 | 10068728 |
| 12 | 53023860 |
| 13 | 280969560 |
| 14 | 1497072132 |
| 15 | 8016213960 |
| 16 | 43114424308 |
| 17 | 232817773640 |
| 18 | 1261793848836 |
| 19 | 6861179441880 |
| 20 | 37421756333172 |
| 21 | 204671007577464 |
| 22 | 1122275850740996 |
| 23 | 6168352091629864 |
| 24 | 33977333521770996 |
| 25 | 187539324760522728 |
[0,1,5,24,116,568,2820,14184,72180,371112,1925380, 10068728,53023860,280969560,1497072132,8016213960, 43114424308,232817773640,1261793848836, 6861179441880,37421756333172,204671007577464, 1122275850740996,6168352091629864, 33977333521770996,187539324760522728] |