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 | 2 |
| 2 | 7 |
| 3 | 227 |
| 4 | 277 |
| 5 | 727 |
| 6 | 2777 |
| 7 | 7727 |
| 8 | 22277 |
| 9 | 22727 |
| 10 | 22777 |
| 11 | 27277 |
| 12 | 72227 |
| 13 | 72277 |
| 14 | 72727 |
| 15 | 272227 |
| 16 | 272777 |
| 17 | 727777 |
| 18 | 777277 |
| 19 | 2227727 |
| 20 | 2227777 |
| 21 | 2272727 |
| 22 | 2277727 |
| 23 | 2727727 |
| 24 | 2772227 |
| 25 | 7272227 |
| 26 | 7722277 |
| 27 | 7727777 |
| 28 | 7772777 |
| 29 | 7777727 |
| 30 | 22227277 |
| 31 | 22272277 |