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 | 1 |
| 1 | 2 |
| 2 | 7 |
| 3 | 31 |
| 4 | 162 |
| 5 | 973 |
| 6 | 6539 |
| 7 | 48410 |
| 8 | 390097 |
| 9 | 3389877 |
| 10 | 31534538 |
| 11 | 312151125 |
| 12 | 3271508959 |
| 13 | 36149187780 |
| 14 | 419604275375 |
| 15 | 5100408982825 |
| 16 | 64743452239424 |
| 17 | 856157851884881 |
| 18 | 11768914560546973 |
| 19 | 167841252874889898 |
| 20 | 2479014206472819045 |
| 21 | 37860543940437797897 |