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 | 1 |
| 2 | 4 |
| 3 | 34 |
| 4 | 364 |
| 5 | 4269 |
| 6 | 52844 |
| 7 | 679172 |
| 8 | 8976188 |
| 9 | 121223668 |
| 10 | 1665558544 |
| 11 | 23207619274 |
| 12 | 327167316436 |
| 13 | 4657884819670 |
| 14 | 66875794530120 |
| 15 | 967202289590280 |
| 16 | 14077773784645980 |
| 17 | 206058395118133932 |
| 18 | 3031188276557963312 |
| 19 | 44789055557553810152 |