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 | 1 |
| 2 | 3 |
| 3 | 7 |
| 4 | 39 |
| 5 | 366 |
| 6 | 5697 |
| 7 | 194881 |
| 8 | 16288695 |
| 9 | 2430565261 |
| 10 | 564615230758 |
| 11 | 257227244037248 |
| 12 | 319346787227133873 |
| 13 | 832952161388710135215 |
| 14 | 3382434539389226013260403 |
| 15 | 22966972221673234523620345857 |