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) |
|---|---|
| 4 | 1 |
| 5 | 13 |
| 6 | 73 |
| 7 | 301 |
| 8 | 1081 |
| 9 | 3613 |
| 10 | 11593 |
| 11 | 36301 |
| 12 | 111961 |
| 13 | 342013 |
| 14 | 1038313 |
| 15 | 3139501 |
| 16 | 9467641 |
| 17 | 28501213 |
| 18 | 85700233 |
| 19 | 257493901 |
| 20 | 773268121 |
| 21 | 2321377213 |
| 22 | 6967277353 |
| 23 | 20908123501 |
| 24 | 62736953401 |
| 25 | 188236026013 |
| 26 | 564758409673 |
| 27 | 1694375892301 |
| 28 | 5083329003481 |
| 29 | 15250389663613 |