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 | 22 |
| 2 | 328 |
| 3 | 4400 |
| 4 | 58140 |
| 5 | 785304 |
| 6 | 11026296 |
| 7 | 162186912 |
| 8 | 2507481216 |
| 9 | 40788301824 |
| 10 | 697929436800 |
| 11 | 12550904017920 |
| 12 | 236908271543040 |
| 13 | 4687098165573120 |
| 14 | 97049168010017280 |
| 15 | 2099830209402931200 |
| 16 | 47405948832458496000 |
| 17 | 1115089078488795648000 |
| 18 | 27290469545695931904000 |
| 19 | 694002594415741341696000 |