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) |
|---|---|
| 8 | 1 |
| 9 | 28 |
| 10 | 546 |
| 11 | 9450 |
| 12 | 165693 |
| 13 | 3065238 |
| 14 | 59919431 |
| 15 | 1226978753 |
| 16 | 26377959608 |
| 17 | 598190993400 |
| 18 | 14328713682920 |
| 19 | 361513209493800 |
| 20 | 9581318478006976 |
| 21 | 266382420824204560 |
| 22 | 7761376103890530800 |
| 23 | 236610865058490439440 |
| 24 | 7532969497593532001856 |
| 25 | 250026557590986469841856 |