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 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | -5 |
| 4 | -23 |
| 5 | -59 |
| 6 | 241 |
| 7 | 2311 |
| 8 | 9745 |
| 9 | -30743 |
| 10 | -529919 |
| 11 | -3161069 |
| 12 | 6984121 |
| 13 | 216832045 |
| 14 | 1696212337 |
| 15 | -2117117729 |
| 16 | -138721306079 |
| 17 | -1359994188719 |
| 18 | 367573878145 |
| 19 | 127713732858667 |
| 20 | 1523067770484361 |
| 21 | 1104033549399061 |
| 22 | -159815269852521359 |
| 23 | -2270787199743845705 |
| 24 | -3946710127731620303 |