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 | 0 |
| 4 | 1 |
| 5 | 3 |
| 6 | 37 |
| 7 | 63 |
| 8 | 479 |
| 9 | 1316 |
| 10 | 8597 |
| 11 | 14619 |
| 12 | 155999 |
| 13 | 211231 |
| 14 | 1732907 |
| 15 | 5302823 |
| 16 | 21559909 |
| 17 | 43398413 |
| 18 | 466495335 |
| 19 | 625545865 |
| 20 | 5659500031 |
| 21 | 15126813765 |
| 22 | 72778025365 |
| 23 | 132561145173 |
| 24 | 1460519554091 |
| 25 | 2338565021382 |