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) |
|---|---|
| 3 | 0 |
| 4 | 18 |
| 5 | 100 |
| 6 | 425 |
| 7 | 1666 |
| 8 | 6370 |
| 9 | 24228 |
| 10 | 92277 |
| 11 | 352594 |
| 12 | 1351933 |
| 13 | 5200130 |
| 14 | 20058103 |
| 15 | 77558534 |
| 16 | 300539938 |
| 17 | 1166802820 |
| 18 | 4537567325 |
| 19 | 17672631538 |
| 20 | 68923264009 |
| 21 | 269128936778 |
| 22 | 1052049481375 |
| 23 | 4116715363270 |
| 24 | 16123801840973 |
| 25 | 63205303218250 |
| 26 | 247959266473375 |
| 27 | 973469712823326 |