Nominations for sequence A400000 are open, see here.
| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 11 |
| 4 | 75 |
| 5 | 694 |
| 6 | 8345 |
| 7 | 123717 |
| 8 | 2177399 |
| 9 | 44317196 |
| 10 | 1023456789 |
| 11 | 26432593615 |
| 12 | 754777787027 |
| 13 | 23609224079778 |
| 14 | 802772380556705 |
| 15 | 29480883458974409 |
| 16 | 1162849439785405935 |
| 17 | 49030176097150555672 |
| 18 | 2200618769387072998445 |
| 19 | 104753196945250864004691 |
| 20 | 5271200265927977839335179 |
[1,2,11,75,694,8345,123717,2177399,44317196, 1023456789,26432593615,754777787027, 23609224079778,802772380556705,29480883458974409, 1162849439785405935,49030176097150555672, 2200618769387072998445,104753196945250864004691, 5271200265927977839335179] |