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 | 1 |
| 2 | 4 |
| 3 | 24 |
| 4 | 196 |
| 5 | 2016 |
| 6 | 24976 |
| 7 | 361792 |
| 8 | 5997872 |
| 9 | 111969552 |
| 10 | 2324081728 |
| 11 | 53089540992 |
| 12 | 1323476327488 |
| 13 | 35752797376128 |
| 14 | 1040367629940352 |
| 15 | 32441861122796672 |
| 16 | 1079239231677587264 |
| 17 | 38151510015777089280 |
| 18 | 1428149538870997774080 |
| 19 | 56435732691153773665280 |