| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 4 |
| 2 | 27 |
| 3 | 233 |
| 4 | 2392 |
| 5 | 28554 |
| 6 | 393642 |
| 7 | 6247511 |
| 8 | 113612460 |
| 9 | 2349157984 |
| 10 | 54693260003 |
| 11 | 1419193978899 |
| 12 | 40649683449268 |
| 13 | 1274332809446116 |
| 14 | 43403931028963260 |
| 15 | 1596092227004496195 |
| 16 | 63024526636437361468 |
| 17 | 2659705693841420725200 |
| 18 | 119463071327339129567836 |
| 19 | 5690148543901378578826660 |
[1,4,27,233,2392,28554,393642,6247511,113612460, 2349157984,54693260003,1419193978899, 40649683449268,1274332809446116,43403931028963260, 1596092227004496195,63024526636437361468, 2659705693841420725200,119463071327339129567836, 5690148543901378578826660] |