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 | 1 |
| 3 | 4 |
| 4 | 16 |
| 5 | 69 |
| 6 | 307 |
| 7 | 1433 |
| 8 | 6903 |
| 9 | 34337 |
| 10 | 175457 |
| 11 | 919525 |
| 12 | 4931233 |
| 13 | 27023894 |
| 14 | 151142376 |
| 15 | 861880778 |
| 16 | 5006906170 |
| 17 | 29611120248 |
| 18 | 178175786593 |
| 19 | 1090266839041 |
| 20 | 6781364484106 |
| 21 | 42858210422338 |
| 22 | 275127506187149 |
| 23 | 1793418517202096 |
| 24 | 11867326044069470 |
| 25 | 79695273536227647 |