| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 129 |
| 3 | 2316 |
| 4 | 18700 |
| 5 | 96825 |
| 6 | 376761 |
| 7 | 1200304 |
| 8 | 3297456 |
| 9 | 8080425 |
| 10 | 18080425 |
| 11 | 37567596 |
| 12 | 73399404 |
| 13 | 136147921 |
| 14 | 241561425 |
| 15 | 412420800 |
| 16 | 680856256 |
| 17 | 1091194929 |
| 18 | 1703414961 |
| 19 | 2597286700 |
| 20 | 3877286700 |
| 21 | 5678375241 |
| 22 | 8172733129 |
| 23 | 11577558576 |
| 24 | 16164030000 |
| 25 | 22267545625 |
[0,1,129,2316,18700,96825,376761,1200304,3297456, 8080425,18080425,37567596,73399404,136147921, 241561425,412420800,680856256,1091194929, 1703414961,2597286700,3877286700,5678375241, 8172733129,11577558576,16164030000,22267545625] |