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 | 3 |
| 3 | 25 |
| 4 | 378 |
| 5 | 8460 |
| 6 | 252087 |
| 7 | 9392890 |
| 8 | 420142350 |
| 9 | 21927528948 |
| 10 | 1307723670020 |
| 11 | 87712176219801 |
| 12 | 6534001434836758 |
| 13 | 535159878432210000 |
| 14 | 47792303301224799288 |
| 15 | 4621416976280491118910 |
| 16 | 481020078381722064175750 |