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 | 29 |
| 3 | 229 |
| 4 | 929 |
| 5 | 2999 |
| 6 | 9929 |
| 7 | 22229 |
| 8 | 99929 |
| 9 | 2222929 |
| 10 | 2229299 |
| 11 | 2292299 |
| 12 | 2299229 |
| 13 | 2922229 |
| 14 | 2992229 |
| 15 | 2992999 |
| 16 | 2999299 |
| 17 | 2999999 |
| 18 | 9222229 |
| 19 | 9922229 |
| 20 | 9929929 |
| 21 | 9929999 |
| 22 | 9999299 |
| 23 | 9999929 |
| 24 | 22229299 |
| 25 | 22292929 |
| 26 | 22299229 |
| 27 | 22929299 |
| 28 | 29229229 |
| 29 | 29229929 |