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 | 0 |
| 3 | 0 |
| 4 | 976 |
| 5 | 18510 |
| 6 | 201528 |
| 7 | 1232448 |
| 8 | 5637824 |
| 9 | 20502396 |
| 10 | 63720920 |
| 11 | 174647286 |
| 12 | 434439792 |
| 13 | 997037470 |
| 14 | 2141831160 |
| 15 | 4348204020 |
| 16 | 8412482304 |
| 17 | 15605151496 |
| 18 | 27903377016 |
| 19 | 48291880442 |
| 20 | 81188237680 |
| 21 | 132977239290 |
| 22 | 212739639640 |