The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 4 |
| 2 | 37 |
| 3 | 379 |
| 4 | 3299 |
| 5 | 27365 |
| 6 | 220299 |
| 7 | 1754781 |
| 8 | 13920341 |
| 9 | 110240626 |
| 10 | 872556370 |
| 11 | 6904697176 |
| 12 | 54631587925 |
| 13 | 432233689525 |
| 14 | 3419633002811 |
| 15 | 27054071815175 |
| 16 | 214033458336670 |
| 17 | 1693278859189788 |
| 18 | 13395969446794951 |
| 19 | 105978853064672169 |
[4,37,379,3299,27365,220299,1754781,13920341, 110240626,872556370,6904697176,54631587925, 432233689525,3419633002811,27054071815175, 214033458336670,1693278859189788, 13395969446794951,105978853064672169] |