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 | 7 |
| 3 | 85 |
| 4 | 415 |
| 5 | 12019 |
| 6 | 13489 |
| 7 | 726301 |
| 8 | 3144919 |
| 9 | 30300391 |
| 10 | 32160403 |
| 11 | 4102360483 |
| 12 | 4301068993 |
| 13 | 758647585777 |
| 14 | 788807993197 |
| 15 | 817534859365 |
| 16 | 3379894237615 |
| 17 | 1007162177631295 |
| 18 | 1036310871245335 |
| 19 | 384227195120585215 |
| 20 | 393975698131531915 |
| 21 | 403382871919715515 |