This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
| 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 |