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 | 101 |
| 2 | 131213 |
| 3 | 171617 |
| 4 | 313031 |
| 5 | 333233 |
| 6 | 434243 |
| 7 | 474647 |
| 8 | 494849 |
| 9 | 636263 |
| 10 | 777677 |
| 11 | 898889 |
| 12 | 939293 |
| 13 | 117116117 |
| 14 | 119118119 |
| 15 | 127126127 |
| 16 | 133132133 |
| 17 | 151150151 |
| 18 | 159158159 |
| 19 | 161160161 |
| 20 | 163162163 |
| 21 | 199198199 |
| 22 | 243242243 |
| 23 | 269268269 |
| 24 | 273272273 |
| 25 | 277276277 |