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 | 47 |
| 4 | 227 |
| 5 | 277 |
| 6 | 727 |
| 7 | 2447 |
| 8 | 2477 |
| 9 | 2777 |
| 10 | 4447 |
| 11 | 7247 |
| 12 | 7477 |
| 13 | 7727 |
| 14 | 22247 |
| 15 | 22277 |
| 16 | 22447 |
| 17 | 22727 |
| 18 | 22777 |
| 19 | 24247 |
| 20 | 27277 |
| 21 | 27427 |
| 22 | 42227 |
| 23 | 42727 |
| 24 | 44777 |
| 25 | 47777 |
| 26 | 72227 |
| 27 | 72277 |
| 28 | 72727 |
| 29 | 74747 |
| 30 | 77447 |
| 31 | 77477 |
| 32 | 77747 |
| 33 | 222247 |
| 34 | 242227 |
| 35 | 242447 |
| 36 | 242747 |
| 37 | 244247 |
| 38 | 244747 |
| 39 | 272227 |