| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 6 |
| 3 | 26 |
| 4 | 125 |
| 5 | 1218 |
| 6 | 8617 |
| 7 | 71334 |
| 8 | 577595 |
| 9 | 4700651 |
| 10 | 38480495 |
| 11 | 314451735 |
| 12 | 2573334509 |
| 13 | 21055448310 |
| 14 | 172301801294 |
| 15 | 1410039149232 |
| 16 | 11539142575254 |
| 17 | 94432464743167 |
| 18 | 772803828389512 |
| 19 | 6324380763604258 |
| 20 | 51756745018300290 |
| 21 | 423561026286439305 |
[0,6,26,125,1218,8617,71334,577595,4700651, 38480495,314451735,2573334509,21055448310, 172301801294,1410039149232,11539142575254, 94432464743167,772803828389512,6324380763604258, 51756745018300290,423561026286439305] |
