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 | 2 |
| 3 | 2 |
| 4 | 12 |
| 5 | 8 |
| 6 | 44 |
| 7 | 192 |
| 8 | 2688 |
| 9 | 1344 |
| 10 | 6896 |
| 11 | 24228 |
| 12 | 316848 |
| 13 | 812624 |
| 14 | 9158880 |
| 15 | 75652512 |
| 16 | 1813091520 |
| 17 | 725236608 |
| 18 | 3568226496 |
| 19 | 11152502816 |
| 20 | 137997707616 |
| 21 | 309878131724 |