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 | 0 |
| 1 | 3 |
| 2 | 10 |
| 3 | 108 |
| 4 | 2166 |
| 5 | 4567 |
| 6 | 38181 |
| 7 | 155830 |
| 8 | 1802916 |
| 9 | 24862120 |
| 10 | 266983762 |
| 11 | 1961835256 |
| 12 | 5916488742 |
| 13 | 19757775943 |
| 14 | 116646786350 |
| 15 | 9611769806236 |
| 16 | 42844700375837 |
| 17 | 275475214363044 |
| 18 | 6789129606004840 |
| 19 | 75182500718243698 |