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 | 0 |
| 1 | 1 |
| 2 | 30 |
| 3 | 424 |
| 4 | 3357 |
| 5 | 17836 |
| 6 | 71769 |
| 7 | 236093 |
| 8 | 667335 |
| 9 | 1676364 |
| 10 | 3832477 |
| 11 | 8113347 |
| 12 | 16112746 |
| 13 | 30319341 |
| 14 | 54481246 |
| 15 | 94072398 |
| 16 | 156878210 |
| 17 | 253719339 |
| 18 | 399333792 |
| 19 | 613438978 |
| 20 | 921996699 |
| 21 | 1358705458 |
| 22 | 1966745847 |
| 23 | 2800806163 |
| 24 | 3929416785 |
| 25 | 5437623230 |
| 26 | 7430029191 |
| 27 | 10034242245 |