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) |
|---|---|
| 2 | 1 |
| 3 | 0 |
| 4 | -4 |
| 5 | -5 |
| 6 | 22 |
| 7 | 98 |
| 8 | -5 |
| 9 | -1458 |
| 10 | -5136 |
| 11 | 9053 |
| 12 | 161328 |
| 13 | 549822 |
| 14 | -1954067 |
| 15 | -30099188 |
| 16 | -114161728 |
| 17 | 500200027 |
| 18 | 8875931202 |
| 19 | 42311243830 |
| 20 | -149028931789 |
| 21 | -3816065804086 |
| 22 | -24704581255020 |
| 23 | 33033659868037 |
| 24 | 2184285021783940 |
| 25 | 20047242475274290 |
| 26 | 30117550563701293 |