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 | 3 |
| 2 | 55 |
| 3 | 253 |
| 4 | 325 |
| 5 | 2775 |
| 6 | 5253 |
| 7 | 255255 |
| 8 | 522753 |
| 9 | 577275 |
| 10 | 2235555 |
| 11 | 2355535 |
| 12 | 2532375 |
| 13 | 3252525 |
| 14 | 3352755 |
| 15 | 7332535 |
| 16 | 23273253 |
| 17 | 25222753 |
| 18 | 37372335 |
| 19 | 55277355 |
| 20 | 73235253 |
| 21 | 222552253 |
| 22 | 273253753 |
| 23 | 325775575 |
| 24 | 337337325 |
| 25 | 577235253 |
| 26 | 2373777253 |