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 | 0 |
| 1 | 1 |
| 2 | 2 |
| 3 | 11 |
| 4 | 77 |
| 5 | 850 |
| 6 | 11047 |
| 7 | 187806 |
| 8 | 3568317 |
| 9 | 82071280 |
| 10 | 2380067130 |
| 11 | 73782081030 |
| 12 | 2729936998114 |
| 13 | 111927416922654 |
| 14 | 4812878927674125 |
| 15 | 226205309600683885 |
| 16 | 11988881408836245894 |
| 17 | 707344003121338507758 |
| 18 | 43147984190401648973266 |