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 | 2 |
| 3 | 8 |
| 4 | 48 |
| 5 | 528 |
| 6 | 5808 |
| 7 | 127776 |
| 8 | 2811072 |
| 9 | 87143232 |
| 10 | 2788583424 |
| 11 | 156160671744 |
| 12 | 6090266198016 |
| 13 | 481131029643264 |
| 14 | 31273516926812160 |
| 15 | 2314240252584099840 |
| 16 | 199024661722232586240 |
| 17 | 27266378655945864314880 |
| 18 | 2508506836347019516968960 |
| 19 | 431463175851687356918661120 |