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 | 1 |
| 3 | 1 |
| 4 | 1 |
| 5 | 1 |
| 6 | 1 |
| 7 | 2 |
| 8 | 16 |
| 9 | 128 |
| 10 | 800 |
| 11 | 4160 |
| 12 | 18944 |
| 13 | 78080 |
| 14 | 301160 |
| 15 | 1208066 |
| 16 | 6753606 |
| 17 | 60823622 |
| 18 | 648980646 |
| 19 | 6581663766 |
| 20 | 60475366230 |
| 21 | 505780634070 |
| 22 | 3921237755958 |
| 23 | 29226687666930 |
| 24 | 227116001463258 |
| 25 | 2092153010685722 |
| 26 | 24250743543656922 |
| 27 | 322040690042341562 |