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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 24 |
| 2 | 299 |
| 3 | 2576 |
| 4 | 17249 |
| 5 | 95656 |
| 6 | 457170 |
| 7 | 1934920 |
| 8 | 7396155 |
| 9 | 25914720 |
| 10 | 84197296 |
| 11 | 256013184 |
| 12 | 734002335 |
| 13 | 1996645640 |
| 14 | 5180091511 |
| 15 | 12874497504 |
| 16 | 30770197710 |
| 17 | 70952341040 |
| 18 | 158302199085 |
| 19 | 342599792520 |
| 20 | 720836052690 |
| 21 | 1477396844040 |
[1,24,299,2576,17249,95656,457170,1934920,7396155, 25914720,84197296,256013184,734002335,1996645640, 5180091511,12874497504,30770197710,70952341040, 158302199085,342599792520,720836052690, 1477396844040] |