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 | 28 |
| 4 | 1625 |
| 5 | 3247268 |
| 6 | 10649997137454 |
| 7 | 113423713055030979289411081 |
| 8 | 12864938683278671740537137672878980378983810317967737 |