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 | 6 |
| 4 | 23 |
| 5 | 103 |
| 6 | 513 |
| 7 | 2760 |
| 8 | 15741 |
| 9 | 93944 |
| 10 | 581303 |
| 11 | 3704045 |
| 12 | 24180340 |
| 13 | 161082639 |
| 14 | 1091681427 |
| 15 | 7508269793 |
| 16 | 52302594344 |
| 17 | 368422746908 |
| 18 | 2620789110712 |
| 19 | 18806093326963 |
| 20 | 136000505625886 |
| 21 | 990406677136685 |
| 22 | 7258100272108212 |