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 | 20 |
| 1 | 21 |
| 2 | 209 |
| 3 | 439 |
| 4 | 4160 |
| 5 | 4599 |
| 6 | 188120 |
| 7 | 192719 |
| 8 | 1922591 |
| 9 | 4037901 |
| 10 | 38263700 |
| 11 | 42301601 |
| 12 | 1730327740 |
| 13 | 1772629341 |
| 14 | 17683991809 |
| 15 | 37140612959 |
| 16 | 351949508440 |
| 17 | 389090121399 |
| 18 | 15915554364400 |
| 19 | 16304644485799 |
| 20 | 162657354736591 |
| 21 | 341619353958981 |
| 22 | 3237231540367420 |