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 | 7 |
| 2 | 63 |
| 3 | 42752 |
| 4 | 57240 |
| 5 | 75422 |
| 6 | 425071 |
| 7 | 574921 |
| 8 | 979527 |
| 9 | 4301392 |
| 10 | 5698600 |
| 11 | 7028665 |
| 12 | 4925000746 |
| 13 | 5074999246 |
| 14 | 7748266573 |
| 15 | 8511881483 |
| 16 | 8814851183 |
| 17 | 7059602159671 |
| 18 | 7106167933827 |
| 19 | 7439286611620 |
| 20 | 7485852385776 |
| 21 | 46791112884924 |