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 | 3 |
| 2 | 21 |
| 3 | 259 |
| 4 | 4681 |
| 5 | 111111 |
| 6 | 3257437 |
| 7 | 113522235 |
| 8 | 4581298449 |
| 9 | 210027483919 |
| 10 | 10778947368421 |
| 11 | 612142982430915 |
| 12 | 38108188628928601 |
| 13 | 2580398988131886039 |
| 14 | 188802050194014479853 |
| 15 | 14843696896551724137931 |
| 16 | 1247923426698972051309601 |
| 17 | 111713733654631566667971615 |