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 | 4 |
| 4 | 2 |
| 5 | 1 |
| 6 | 77 |
| 7 | 29 |
| 8 | -4289 |
| 9 | -14836 |
| 10 | 283812 |
| 11 | 1316855 |
| 12 | -16548717 |
| 13 | -292820579 |
| 14 | 911200565 |
| 15 | 52594983250 |
| 16 | 100157634380 |
| 17 | -3444629077653 |
| 18 | 7961210574683 |
| 19 | -2170805244559295 |
| 20 | -41176659971108705 |
| 21 | 348776485253486302 |
| 22 | 35663019455311634058 |
| 23 | 513993485453689440281 |