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 | 4 |
| 4 | 25 |
| 5 | 96 |
| 6 | 481 |
| 7 | 3368 |
| 8 | 20721 |
| 9 | 141760 |
| 10 | 1146721 |
| 11 | 9098112 |
| 12 | 77652169 |
| 13 | 726208640 |
| 14 | 6891125697 |
| 15 | 69344336896 |
| 16 | 738718169569 |
| 17 | 8076031881216 |
| 18 | 92647353941569 |
| 19 | 1106883171037184 |
| 20 | 13616813607795321 |
| 21 | 174298975125127168 |
| 22 | 2304515271134124577 |