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 | 2 |
| 2 | 7 |
| 3 | 34 |
| 4 | 211 |
| 5 | 1564 |
| 6 | 13291 |
| 7 | 126430 |
| 8 | 1326211 |
| 9 | 15184744 |
| 10 | 188348659 |
| 11 | 2515991290 |
| 12 | 36018842875 |
| 13 | 550317892372 |
| 14 | 8940695112331 |
| 15 | 153950966471734 |
| 16 | 2801321782936819 |
| 17 | 53720913548093344 |
| 18 | 1083061044893428675 |