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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 14 |
| 2 | 142 |
| 3 | 1252 |
| 4 | 10190 |
| 5 | 78724 |
| 6 | 586236 |
| 7 | 4247688 |
| 8 | 30132438 |
| 9 | 210175540 |
| 10 | 1445920388 |
| 11 | 9833940472 |
| 12 | 66237449356 |
| 13 | 442463439656 |
| 14 | 2934485313400 |
| 15 | 19340115356688 |
| 16 | 126759642351462 |
| 17 | 826734451831956 |
| 18 | 5368338057048756 |
| 19 | 34721155684000920 |
| 20 | 223765535492622564 |
| 21 | 1437403425873718776 |
[1,14,142,1252,10190,78724,586236,4247688, 30132438,210175540,1445920388,9833940472, 66237449356,442463439656,2934485313400, 19340115356688,126759642351462,826734451831956, 5368338057048756,34721155684000920, 223765535492622564,1437403425873718776] |