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 | 1 |
| 2 | 5 |
| 3 | 21 |
| 4 | 357 |
| 5 | 5797 |
| 6 | 376805 |
| 7 | 24208613 |
| 8 | 6221613541 |
| 9 | 1594283908581 |
| 10 | 1634141006295525 |
| 11 | 1673768626404966885 |
| 12 | 6857430062381149327845 |
| 13 | 28089747579101385828291045 |
| 14 | 460250514083576206796548772325 |
| 15 | 7540859480106603961931048583270885 |