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 | 55 |
| 2 | 2775 |
| 3 | 255255 |
| 4 | 577275 |
| 5 | 572755525755 |
| 6 | 2577527227575 |
| 7 | 727275225222727525 |
| 8 | 2257227755272522252275 |
| 9 | 52722757572552577725225 |
| 10 | 272527775757277272275522727772752527575 |