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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 23 |
| 2 | 299 |
| 3 | 2898 |
| 4 | 23184 |
| 5 | 161253 |
| 6 | 1006250 |
| 7 | 5751679 |
| 8 | 30558053 |
| 9 | 152543797 |
| 10 | 721432513 |
| 11 | 3253563394 |
| 12 | 14065808815 |
| 13 | 58544010641 |
| 14 | 235435351628 |
| 15 | 917591584210 |
| 16 | 3474891526923 |
| 17 | 12815003028813 |
| 18 | 46113476682975 |
[1,23,299,2898,23184,161253,1006250,5751679, 30558053,152543797,721432513,3253563394, 14065808815,58544010641,235435351628,917591584210, 3474891526923,12815003028813,46113476682975] |