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 | 0 |
| 1 | 0 |
| 2 | 1 |
| 3 | 1 |
| 4 | 12 |
| 5 | 8 |
| 6 | 112 |
| 7 | 71 |
| 8 | 1472 |
| 9 | 1269 |
| 10 | 17408 |
| 11 | 14904 |
| 12 | 270336 |
| 13 | 204147 |
| 14 | 4199424 |
| 15 | 4143285 |
| 16 | 87834624 |
| 17 | 72462870 |
| 18 | 1797783552 |
| 19 | 1411253955 |
| 20 | 40414740480 |
| 21 | 36183623805 |
| 22 | 937430876160 |
| 23 | 845972658090 |
| 24 | 26095323709440 |
| 25 | 24311657884500 |
| 26 | 707908274749440 |
| 27 | 869872809558375 |