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) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 13 |
| 4 | 15 |
| 5 | 28 |
| 6 | 1359 |
| 7 | 1387 |
| 8 | 2746 |
| 9 | 17863 |
| 10 | 20609 |
| 11 | 38472 |
| 12 | 1867265 |
| 13 | 1905737 |
| 14 | 3773002 |
| 15 | 24543749 |
| 16 | 28316751 |
| 17 | 52860500 |
| 18 | 2565620751 |
| 19 | 2618481251 |
| 20 | 5184102002 |
| 21 | 33723093263 |
| 22 | 38907195265 |
| 23 | 72630288528 |
| 24 | 3525161044609 |
| 25 | 3597791333137 |
| 26 | 7122952377746 |
| 27 | 46335505599613 |