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) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 3 |
| 4 | 21 |
| 5 | 39 |
| 6 | 288 |
| 7 | 309 |
| 8 | 1659 |
| 9 | 3102 |
| 10 | 14148 |
| 11 | 17157 |
| 12 | 136227 |
| 13 | 130995 |
| 14 | 790128 |
| 15 | 1791489 |
| 16 | 5427597 |
| 17 | 8047839 |
| 18 | 64467180 |
| 19 | 64486017 |
| 20 | 437324331 |
| 21 | 871627041 |
| 22 | 3136899816 |
| 23 | 4278115101 |
| 24 | 35355632943 |
| 25 | 42359479638 |