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 | 0 |
| 2 | 6480 |
| 3 | 157680 |
| 4 | 1596510 |
| 5 | 9488016 |
| 6 | 40681440 |
| 7 | 140492880 |
| 8 | 406046520 |
| 9 | 1047312720 |
| 10 | 2426695200 |
| 11 | 5208293520 |
| 12 | 10421250750 |
| 13 | 19873356480 |
| 14 | 35716191840 |
| 15 | 62355291696 |
| 16 | 104234541390 |
| 17 | 169488573120 |
| 18 | 267064691760 |
| 19 | 413777075760 |
| 20 | 619573504896 |
| 21 | 920235334320 |
| 22 | 1331744781600 |