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 | 5 |
| 3 | 32 |
| 4 | 292 |
| 5 | 3294 |
| 6 | 44918 |
| 7 | 714468 |
| 8 | 13002456 |
| 9 | 266275200 |
| 10 | 6060498672 |
| 11 | 151750887936 |
| 12 | 4145522908272 |
| 13 | 122690391196944 |
| 14 | 3910569680464848 |
| 15 | 133549150323123744 |
| 16 | 4864927063250290176 |
| 17 | 188297220693251438208 |
| 18 | 7716800776602560577408 |