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 | 4 |
| 2 | 2 |
| 3 | 8 |
| 4 | 48 |
| 5 | 288 |
| 6 | 1728 |
| 7 | 10368 |
| 8 | 62208 |
| 9 | 373248 |
| 10 | 2239488 |
| 11 | 13436928 |
| 12 | 80621568 |
| 13 | 483729408 |
| 14 | 2902376448 |
| 15 | 17414258688 |
| 16 | 104485552128 |
| 17 | 626913312768 |
| 18 | 3761479876608 |
| 19 | 22568879259648 |
| 20 | 135413275557888 |
| 21 | 812479653347328 |
| 22 | 4874877920083968 |
| 23 | 29249267520503808 |