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 | 0 |
| 2 | 1 |
| 3 | 4 |
| 4 | 49 |
| 5 | 792 |
| 6 | 18953 |
| 7 | 610796 |
| 8 | 25648641 |
| 9 | 1359184384 |
| 10 | 88722005809 |
| 11 | 6994262098260 |
| 12 | 655126226755025 |
| 13 | 71915748374032232 |
| 14 | 9144536677714434105 |
| 15 | 1333394182537641307324 |
| 16 | 221002933797466121742433 |