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 | 0 |
| 3 | -1 |
| 4 | 2 |
| 5 | 1 |
| 6 | -26 |
| 7 | 99 |
| 8 | 90 |
| 9 | -3627 |
| 10 | 21054 |
| 11 | 21735 |
| 12 | -1465278 |
| 13 | 11769033 |
| 14 | 10145862 |
| 15 | -1292734485 |
| 16 | 13592476842 |
| 17 | 5651236989 |
| 18 | -2114795158962 |
| 19 | 28081762413807 |
| 20 | -8040489684078 |
| 21 | -5763467251713423 |
| 22 | 94263221264053590 |
| 23 | -115569462262872717 |
| 24 | -24259606258553011206 |
| 25 | 479901663461939425317 |