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 | 3 |
| 3 | 20 |
| 4 | 247 |
| 5 | 1861 |
| 6 | 28669 |
| 7 | 202564 |
| 8 | 12127115 |
| 9 | 115222124 |
| 10 | 6126483469 |
| 11 | 19465244918 |
| 12 | 4282552771669 |
| 13 | 4226847828547 |
| 14 | 3334905643119667 |
| 15 | 311202902635062863 |
| 16 | 13506468355090939237 |
| 17 | 455126377640041434982 |
| 18 | 3558300899222541879853 |