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 | 3 |
| 3 | 11 |
| 4 | 72 |
| 5 | 473 |
| 6 | 3727 |
| 7 | 39646 |
| 8 | 412679 |
| 9 | 4765654 |
| 10 | 61015451 |
| 11 | 937386045 |
| 12 | 14126033578 |
| 13 | 227901084348 |
| 14 | 3941375013541 |
| 15 | 72677938745613 |
| 16 | 1517730017193292 |
| 17 | 31249446089387086 |
| 18 | 675658943143264102 |
| 19 | 15356377683044270187 |