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) |
|---|---|
| 2 | 2 |
| 3 | 4 |
| 4 | 8 |
| 5 | 28 |
| 6 | 128 |
| 7 | 748 |
| 8 | 5168 |
| 9 | 41068 |
| 10 | 368048 |
| 11 | 3669868 |
| 12 | 40284848 |
| 13 | 482671468 |
| 14 | 6267305648 |
| 15 | 87660962668 |
| 16 | 1313941673648 |
| 17 | 21010450850668 |
| 18 | 357001369769648 |
| 19 | 6423384156578668 |
| 20 | 122002101778601648 |
| 21 | 2439325392333218668 |