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) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 5 |
| 3 | 16 |
| 4 | 97 |
| 5 | 2186 |
| 6 | 57661 |
| 7 | 1018732 |
| 8 | 13546529 |
| 9 | 1146511702 |
| 10 | 102660872221 |
| 11 | 2825817094376 |
| 12 | -145181157396863 |
| 13 | 13773236811700354 |
| 14 | 5271279146947177757 |
| 15 | 116514699193035121156 |
| 16 | -76433013927946696971839 |
| 17 | 1553218338489700863557582 |
| 18 | 3403068210845899797768538429 |