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 | 1 |
| 2 | 3 |
| 3 | 19 |
| 4 | 357 |
| 5 | 36301 |
| 6 | 25099919 |
| 7 | 125586786039 |
| 8 | 5057589140280713 |
| 9 | 1834978988294513263993 |
| 10 | 6658624933768189847669906875 |
| 11 | 265790340541205664455435665865706651 |
| 12 | 127313966488883223582008076686428073754622381 |
| 13 | 792786699250878346141762323574616271109902136066501317 |