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| n | a(n) |
|---|---|
| 2 | 1 |
| 3 | 7 |
| 4 | 38 |
| 5 | 190 |
| 6 | 918 |
| 7 | 4365 |
| 8 | 20594 |
| 9 | 96804 |
| 10 | 454362 |
| 11 | 2132121 |
| 12 | 10010203 |
| 13 | 47042042 |
| 14 | 221337726 |
| 15 | 1042837195 |
| 16 | 4920447410 |
| 17 | 23250646651 |
| 18 | 110029743083 |
| 19 | 521462857972 |
| 20 | 2474929099976 |
| 21 | 11762845907633 |
| 22 | 55982738983975 |
| 23 | 266789302547057 |
[1,7,38,190,918,4365,20594,96804,454362,2132121, 10010203,47042042,221337726,1042837195,4920447410, 23250646651,110029743083,521462857972, 2474929099976,11762845907633,55982738983975, 266789302547057] |