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 | 1 |
| 3 | 4 |
| 4 | 18 |
| 5 | 97 |
| 6 | 607 |
| 7 | 4358 |
| 8 | 35523 |
| 9 | 324356 |
| 10 | 3280902 |
| 11 | 36427352 |
| 12 | 440515699 |
| 13 | 5764104507 |
| 14 | 81147821501 |
| 15 | 1223090709078 |
| 16 | 19651920713844 |
| 17 | 335323035157947 |
| 18 | 6055709997021397 |
| 19 | 115397482250691724 |
| 20 | 2314064310772997407 |
| 21 | 48711753977589111112 |
| 22 | 1073990818947724506060 |