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) |
|---|---|
| 3 | 1 |
| 4 | 5 |
| 5 | 18 |
| 6 | 95 |
| 7 | 600 |
| 8 | 4307 |
| 9 | 35168 |
| 10 | 321609 |
| 11 | 3257109 |
| 12 | 36199762 |
| 13 | 438126986 |
| 14 | 5736774126 |
| 15 | 80808984725 |
| 16 | 1218563180295 |
| 17 | 19587031966352 |
| 18 | 334329804347219 |
| 19 | 6039535339644630 |
| 20 | 115118210694558105 |
| 21 | 2308967760171049528 |
| 22 | 48613722701436777455 |
| 23 | 1072008447320752890459 |