| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 6 |
| 2 | 39 |
| 3 | 327 |
| 4 | 3107 |
| 5 | 31616 |
| 6 | 337175 |
| 7 | 3715296 |
| 8 | 41913438 |
| 9 | 481269293 |
| 10 | 5602858280 |
| 11 | 65950014530 |
| 12 | 783308042567 |
| 13 | 9373678643933 |
| 14 | 112887433941997 |
| 15 | 1366927164653291 |
| 16 | 16630083791845124 |
| 17 | 203159420763091245 |
| 18 | 2490934476522213505 |
| 19 | 30640433478257977941 |
[0,6,39,327,3107,31616,337175,3715296,41913438, 481269293,5602858280,65950014530,783308042567, 9373678643933,112887433941997,1366927164653291, 16630083791845124,203159420763091245, 2490934476522213505,30640433478257977941] |