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 | 215 |
| 5 | 1698 |
| 6 | 16220 |
| 7 | 182714 |
| 8 | 2378780 |
| 9 | 35219202 |
| 10 | 585245185 |
| 11 | 10797322816 |
| 12 | 219163958124 |
| 13 | 4856832298391 |
| 14 | 116735215192864 |
| 15 | 3025759884533190 |
| 16 | 84155831914971391 |
| 17 | 2500599947944218716 |
| 18 | 79072271422935678302 |