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 | 648 |
| 1 | -5400 |
| 2 | 15336 |
| 3 | -20088 |
| 4 | 100872 |
| 5 | -105624 |
| 6 | 599400 |
| 7 | -604152 |
| 8 | 3505032 |
| 9 | -3509784 |
| 10 | 20440296 |
| 11 | -20445048 |
| 12 | 119146248 |
| 13 | -119151000 |
| 14 | 694446696 |
| 15 | -694451448 |
| 16 | 4047543432 |
| 17 | -4047548184 |
| 18 | 23590823400 |
| 19 | -23590828152 |
| 20 | 137497406472 |
| 21 | -137497411224 |
| 22 | 801393624936 |
| 23 | -801393629688 |