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 | 5 |
| 4 | 28 |
| 5 | 159 |
| 6 | 1383 |
| 7 | 16818 |
| 8 | 168974 |
| 9 | 2921624 |
| 10 | 43918848 |
| 11 | 1166660928 |
| 12 | 31828563776 |
| 13 | 1193792259072 |
| 14 | 43520679101184 |
| 15 | 1622694957527040 |