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 | 18 |
| 3 | 114 |
| 4 | 750 |
| 5 | 5058 |
| 6 | 34692 |
| 7 | 240852 |
| 8 | 1687446 |
| 9 | 11906610 |
| 10 | 84490428 |
| 11 | 602335836 |
| 12 | 4310670156 |
| 13 | 30950436468 |
| 14 | 222844189320 |
| 15 | 1608369633384 |
| 16 | 11632913018598 |
| 17 | 84294762019218 |
| 18 | 611831430746124 |
| 19 | 4447397950230540 |