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 | 4 |
| 2 | 28 |
| 3 | 256 |
| 4 | 2716 |
| 5 | 31504 |
| 6 | 387136 |
| 7 | 4951552 |
| 8 | 65218204 |
| 9 | 878536624 |
| 10 | 12046924528 |
| 11 | 167595457792 |
| 12 | 2359613230144 |
| 13 | 33557651538688 |
| 14 | 481365424895488 |
| 15 | 6956365106016256 |
| 16 | 101181938814289564 |
| 17 | 1480129751586116848 |
| 18 | 21761706991570726096 |
| 19 | 321401321741959062016 |