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 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 6 |
| 5 | 15 |
| 6 | 255 |
| 7 | 1897 |
| 8 | 92263 |
| 9 | 1972653 |
| 10 | 281035054 |
| 11 | 17635484470 |
| 12 | 7490694495750 |
| 13 | 1405083604458437 |
| 14 | 1789509008288411290 |