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 | 0 |
| 2 | 0 |
| 3 | 131 |
| 4 | 2221 |
| 5 | 263 |
| 6 | 1039 |
| 7 | 2591 |
| 8 | 2719 |
| 9 | 4397 |
| 10 | 57089 |
| 11 | 79609 |
| 12 | 479881 |
| 13 | 2557967 |
| 14 | 1299499 |
| 15 | 8796629 |
| 16 | 49979249 |
| 17 | 349929779 |
| 18 | 753987769 |
| 19 | 1397989867 |
| 20 | 8278487999 |
| 21 | 16874789779 |
| 22 | 69355889899 |
| 23 | 199785963989 |
| 24 | 1787899947299 |
| 25 | 17678888878867 |