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 | 3 |
| 3 | 14 |
| 4 | 91 |
| 5 | 820 |
| 6 | 9650 |
| 7 | 140601 |
| 8 | 2440317 |
| 9 | 49109632 |
| 10 | 1123595495 |
| 11 | 28792920872 |
| 12 | 816742025772 |
| 13 | 25402428294801 |
| 14 | 859492240650847 |
| 15 | 31427791175659690 |
| 16 | 1234928473553777403 |
| 17 | 51893300561135516404 |
| 18 | 2322083099525697299278 |