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 | 2 |
| 3 | 21 |
| 4 | 402 |
| 5 | 13805 |
| 6 | 761154 |
| 7 | 62523664 |
| 8 | 7237970648 |
| 9 | 1132600004910 |
| 10 | 231900134422880 |
| 11 | 60528794385067778 |
| 12 | 19713593779259862624 |
| 13 | 7869483395065035685162 |
| 14 | 3792402572391137423764584 |