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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 72 |
| 3 | 1134 |
| 4 | 8320 |
| 5 | 39375 |
| 6 | 140616 |
| 7 | 412972 |
| 8 | 1050624 |
| 9 | 2394765 |
| 10 | 5005000 |
| 11 | 9750906 |
| 12 | 17926272 |
| 13 | 31388539 |
| 14 | 52725960 |
| 15 | 85455000 |
| 16 | 134250496 |
| 17 | 205211097 |
| 18 | 306162504 |
| 19 | 447001030 |
| 20 | 640080000 |
| 21 | 900641511 |
| 22 | 1247296072 |
| 23 | 1702552644 |
| 24 | 2293401600 |
[0,1,72,1134,8320,39375,140616,412972,1050624, 2394765,5005000,9750906,17926272,31388539, 52725960,85455000,134250496,205211097,306162504, 447001030,640080000,900641511,1247296072, 1702552644,2293401600] |