The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 2 |
| 2 | 5 |
| 3 | 39 |
| 4 | 87 |
| 5 | 629 |
| 6 | 1394 |
| 7 | 10032 |
| 8 | 22224 |
| 9 | 159890 |
| 10 | 354197 |
| 11 | 2548215 |
| 12 | 5644935 |
| 13 | 40611557 |
| 14 | 89964770 |
| 15 | 647236704 |
| 16 | 1433791392 |
| 17 | 10315175714 |
| 18 | 22850697509 |
| 19 | 164395574727 |
| 20 | 364177368759 |
| 21 | 2620014019925 |
| 22 | 5803987202642 |
| 23 | 41755828744080 |
| 24 | 92499617873520 |
| 25 | 665473245885362 |
[0,2,5,39,87,629,1394,10032,22224,159890,354197, 2548215,5644935,40611557,89964770,647236704, 1433791392,10315175714,22850697509,164395574727, 364177368759,2620014019925,5803987202642, 41755828744080,92499617873520,665473245885362] |