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 | 6 |
| 3 | 20 |
| 4 | 141 |
| 5 | 7770 |
| 6 | 204372 |
| 7 | 16260853 |
| 8 | 4570906041 |
| 9 | 1437642613959 |
| 10 | 1151580438927120 |