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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 14 |
| 3 | 110 |
| 4 | 682 |
| 5 | 3731 |
| 6 | 18928 |
| 7 | 91392 |
| 8 | 426360 |
| 9 | 1939938 |
| 10 | 8662214 |
| 11 | 38119510 |
| 12 | 165828390 |
| 13 | 714707175 |
| 14 | 3056887680 |
| 15 | 12991772640 |
| 16 | 54919766160 |
| 17 | 231102342990 |
| 18 | 968661801900 |
| 19 | 4046295064812 |
| 20 | 16851791934516 |
| 21 | 69999056422526 |
| 22 | 290085110464864 |
| 23 | 1199652675300800 |
| 24 | 4951946963738320 |
| 25 | 20406434266878660 |
[1,14,110,682,3731,18928,91392,426360,1939938, 8662214,38119510,165828390,714707175,3056887680, 12991772640,54919766160,231102342990,968661801900, 4046295064812,16851791934516,69999056422526, 290085110464864,1199652675300800,4951946963738320, 20406434266878660] |