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 | 4 |
| 2 | 25 |
| 3 | 225 |
| 4 | 4225 |
| 5 | 55225 |
| 6 | 442225 |
| 7 | 4545424 |
| 8 | 5452225 |
| 9 | 42445225 |
| 10 | 44422225 |
| 11 | 544522225 |
| 12 | 2224254244 |
| 13 | 4424245225 |
| 14 | 4444222225 |
| 15 | 4554225225 |
| 16 | 54445222225 |
| 17 | 55255554225 |
| 18 | 444242245225 |
| 19 | 444442222225 |
| 20 | 5444452222225 |
| 21 | 44442422245225 |
| 22 | 44444422222225 |
| 23 | 544444522222225 |