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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 38 |
| 3 | 404 |
| 4 | 5510 |
| 5 | 74492 |
| 6 | 1048924 |
| 7 | 15004776 |
| 8 | 217943238 |
| 9 | 3200089580 |
| 10 | 47405806708 |
| 11 | 707305846936 |
| 12 | 10616181542044 |
| 13 | 160142807848792 |
| 14 | 2426097698458360 |
| 15 | 36890818642990544 |
| 16 | 562772826273060678 |
| 17 | 8609639617006367052 |
| 18 | 132048790603779592196 |
| 19 | 2029851945081220214200 |
[1,2,38,404,5510,74492,1048924,15004776,217943238, 3200089580,47405806708,707305846936, 10616181542044,160142807848792,2426097698458360, 36890818642990544,562772826273060678, 8609639617006367052,132048790603779592196, 2029851945081220214200] |