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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 8 |
| 4 | 63 |
| 5 | 893 |
| 6 | 19714 |
| 7 | 597510 |
| 8 | 22903403 |
| 9 | 1056115331 |
| 10 | 56744710974 |
| 11 | 3475626211316 |
| 12 | 238818544070905 |
| 13 | 18183183610029003 |
| 14 | 1519020289266947462 |
| 15 | 138117136134012654182 |
| 16 | 13576724206357958780409 |
| 17 | 1434561741418662640589225 |
| 18 | 162136032834834405685977058 |
| 19 | 19516966563322659948894106704 |
[1,1,2,8,63,893,19714,597510,22903403,1056115331, 56744710974,3475626211316,238818544070905, 18183183610029003,1519020289266947462, 138117136134012654182,13576724206357958780409, 1434561741418662640589225, 162136032834834405685977058, 19516966563322659948894106704] |