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 | 9 |
| 2 | 90 |
| 3 | 945 |
| 4 | 10206 |
| 5 | 112266 |
| 6 | 1250964 |
| 7 | 14073345 |
| 8 | 159497910 |
| 9 | 1818276174 |
| 10 | 20827527084 |
| 11 | 239516561466 |
| 12 | 2763652632300 |
| 13 | 31979409030900 |
| 14 | 370961144758440 |
| 15 | 4312423307816865 |
| 16 | 50227047938102310 |
| 17 | 585982225944526950 |
| 18 | 6846739692614999100 |
| 19 | 80106854403595489470 |
| 20 | 938394580156404305220 |