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 | 18 |
| 2 | 235 |
| 3 | 2700 |
| 4 | 28981 |
| 5 | 298278 |
| 6 | 2984095 |
| 7 | 29253600 |
| 8 | 282456361 |
| 9 | 2695498938 |
| 10 | 25486623955 |
| 11 | 239196683700 |
| 12 | 2231306698141 |
| 13 | 20710052641998 |
| 14 | 191416812647815 |
| 15 | 1762962024789000 |
| 16 | 16188343910770321 |
| 17 | 148268580698287458 |
| 18 | 1355005110295423675 |
| 19 | 12359749064745505500 |