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 | 1 |
| 3 | 210 |
| 4 | 40755 |
| 5 | 7906276 |
| 6 | 1533776805 |
| 7 | 297544793910 |
| 8 | 57722156241751 |
| 9 | 11197800766105800 |
| 10 | 2172315626468283465 |
| 11 | 421418033734080886426 |
| 12 | 81752926228785223683195 |
| 13 | 15859646270350599313653420 |