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 | 3 |
| 2 | 15 |
| 3 | 63 |
| 4 | 135 |
| 5 | 99 |
| 6 | 12285 |
| 7 | 405 |
| 8 | 6885 |
| 9 | 161595 |
| 10 | 1403325 |
| 11 | 419175 |
| 12 | 24877125 |
| 13 | 229635 |
| 14 | 528525 |
| 15 | 26101845 |
| 16 | 214708725 |
| 17 | 1148175 |
| 18 | 31479513975 |
| 19 | 134336475 |
| 20 | 23302211625 |
| 21 | 513217002375 |
| 22 | 374333754375 |
| 23 | 50996192625 |
| 24 | 25178013826875 |
| 25 | 678264862275 |
| 26 | 813304020375 |
| 27 | 6122798191125 |