| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 4 |
| 2 | 28 |
| 3 | 340 |
| 4 | 7108 |
| 5 | 254404 |
| 6 | 15531268 |
| 7 | 1613235460 |
| 8 | 284556079108 |
| 9 | 85107970698244 |
| 10 | 43112647751430148 |
| 11 | 36955277740855136260 |
| 12 | 53562598422461559373828 |
| 13 | 131186989945696839128432644 |
| 14 | 542676256323680030599454982148 |
[1,4,28,340,7108,254404,15531268,1613235460, 284556079108,85107970698244,43112647751430148, 36955277740855136260,53562598422461559373828, 131186989945696839128432644, 542676256323680030599454982148] |