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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 4 |
| 3 | 26 |
| 4 | 226 |
| 5 | 2395 |
| 6 | 29278 |
| 7 | 398499 |
| 8 | 5899534 |
| 9 | 93507783 |
| 10 | 1569405110 |
| 11 | 27672405800 |
| 12 | 509622262860 |
| 13 | 9759305238932 |
| 14 | 193673399146066 |
| 15 | 3972141366536794 |
| 16 | 84010899306559470 |
| 17 | 1829057795368804875 |
| 18 | 40931310532585505770 |
| 19 | 940322157062673670051 |
| 20 | 22152626055397162566438 |
[1,1,4,26,226,2395,29278,398499,5899534,93507783, 1569405110,27672405800,509622262860,9759305238932, 193673399146066,3972141366536794, 84010899306559470,1829057795368804875, 40931310532585505770,940322157062673670051, 22152626055397162566438] |