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 | 8 |
| 3 | 53 |
| 4 | 473 |
| 5 | 5198 |
| 6 | 67568 |
| 7 | 1013513 |
| 8 | 17229713 |
| 9 | 327364538 |
| 10 | 6874655288 |
| 11 | 158117071613 |
| 12 | 3952926790313 |
| 13 | 106729023338438 |
| 14 | 3095141676814688 |
| 15 | 95949391981255313 |
| 16 | 3166329935381425313 |
| 17 | 110821547738349885938 |
| 18 | 4100397266318945779688 |
| 19 | 159915493386438885407813 |