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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 28 |
| 2 | 184 |
| 3 | 1232 |
| 4 | 8304 |
| 5 | 56196 |
| 6 | 381296 |
| 7 | 2592000 |
| 8 | 17644932 |
| 9 | 120248704 |
| 10 | 820197868 |
| 11 | 5598376276 |
| 12 | 38234454860 |
| 13 | 261248031956 |
| 14 | 1785751586164 |
| 15 | 12210406222304 |
| 16 | 83513470631012 |
| 17 | 571321692051188 |
| 18 | 3909186587411576 |
| 19 | 26752234815389416 |
[1,28,184,1232,8304,56196,381296,2592000,17644932, 120248704,820197868,5598376276,38234454860, 261248031956,1785751586164,12210406222304, 83513470631012,571321692051188,3909186587411576, 26752234815389416] |