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) |
|---|---|
| 1 | 7 |
| 2 | 19 |
| 3 | 12503 |
| 4 | 40000000003 |
| 5 | 8203095294242440214580822436689504141944719346082430189179667864757469187 |