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 | 0 |
| 3 | 1 |
| 4 | 1 |
| 5 | 3 |
| 6 | 10 |
| 7 | 39 |
| 8 | 173 |
| 9 | 882 |
| 10 | 5052 |
| 11 | 32163 |
| 12 | 225230 |
| 13 | 1720635 |
| 14 | 14240070 |
| 15 | 126917155 |
| 16 | 1211969509 |
| 17 | 12345020175 |
| 18 | 133604426410 |
| 19 | 1530993953307 |
| 20 | 18518559411876 |
| 21 | 235785621577351 |
| 22 | 3152221563324450 |
| 23 | 44148864630732711 |
| 24 | 646438923481545230 |
| 25 | 9876859207608319344 |
| 26 | 157195096511273995860 |