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 | 1 |
| 1 | 288 |
| 2 | 15776 |
| 3 | 346304 |
| 4 | 4254912 |
| 5 | 34792672 |
| 6 | 210482016 |
| 7 | 1010803584 |
| 8 | 4047994752 |
| 9 | 14009305760 |
| 10 | 43023042336 |
| 11 | 119628650560 |
| 12 | 305908697152 |
| 13 | 728298521184 |
| 14 | 1630273964256 |
| 15 | 3458692036352 |
| 16 | 7000203482880 |
| 17 | 13590066551840 |
| 18 | 25423081113760 |
| 19 | 46005461684160 |
| 20 | 80797523590080 |