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 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 4 |
| 4 | 13 |
| 5 | 57 |
| 6 | 322 |
| 7 | 2176 |
| 8 | 17009 |
| 9 | 150505 |
| 10 | 1485466 |
| 11 | 16170036 |
| 12 | 192384877 |
| 13 | 2483177809 |
| 14 | 34554278858 |
| 15 | 515620794592 |
| 16 | 8212685046337 |
| 17 | 139062777326001 |
| 18 | 2494364438359954 |
| 19 | 47245095998005060 |
| 20 | 942259727190907181 |
| 21 | 19737566982241851721 |
| 22 | 433234326593362631602 |