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 | 2 |
| 3 | 3 |
| 4 | 7 |
| 5 | 26 |
| 6 | 55 |
| 7 | 282 |
| 8 | 1520 |
| 9 | 2685 |
| 10 | 27005 |
| 11 | 171474 |
| 12 | 768123 |
| 13 | 5936728 |
| 14 | 43976303 |
| 15 | 207493790 |
| 16 | 2570789335 |
| 17 | 21669733984 |
| 18 | 136340261314 |
| 19 | 1639978185920 |