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 | 5 |
| 3 | 14 |
| 4 | 61 |
| 5 | 243 |
| 6 | 1228 |
| 7 | 6684 |
| 8 | 42681 |
| 9 | 304569 |
| 10 | 2445296 |
| 11 | 21676143 |
| 12 | 210409238 |
| 13 | 2213794888 |
| 14 | 25064493886 |
| 15 | 303468325469 |
| 16 | 3909518220091 |
| 17 | 53364222428953 |
| 18 | 769009695515272 |
| 19 | 11663042823897054 |
| 20 | 185651491398956596 |
| 21 | 3094082786005252494 |
| 22 | 53871873427160960819 |