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) |
|---|---|
| 0 | 2 |
| 1 | 7 |
| 2 | 1847 |
| 3 | 90793 |
| 4 | 139313 |
| 5 | 1790293 |
| 6 | 3834043 |
| 7 | 5521543 |
| 8 | 24996487 |
| 9 | 2062865293 |
| 10 | 5555052793 |
| 11 | 12111965183 |
| 12 | 95460776921 |
| 13 | 6045070151921 |
| 14 | 10204150316653 |
| 15 | 70501997496487 |
| 16 | 442748358250633 |
| 17 | 368313674465183 |
| 18 | 2935956099058987 |
| 19 | 10360552690003447 |
| 20 | 120999670013476223 |
| 21 | 1820610211470152737 |