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 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 5 |
| 5 | 10 |
| 6 | 32 |
| 7 | 64 |
| 8 | 231 |
| 9 | 462 |
| 10 | 1792 |
| 11 | 3584 |
| 12 | 14586 |
| 13 | 29172 |
| 14 | 122880 |
| 15 | 245760 |
| 16 | 1062347 |
| 17 | 2124694 |
| 18 | 9371648 |
| 19 | 18743296 |
| 20 | 84021990 |
| 21 | 168043980 |
| 22 | 763363328 |
| 23 | 1526726656 |
| 24 | 7012604550 |
| 25 | 14025209100 |
| 26 | 65028489216 |
| 27 | 130056978432 |
| 28 | 607892634420 |