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 | 2 |
| 2 | 0 |
| 3 | -10 |
| 4 | -22 |
| 5 | 12 |
| 6 | 174 |
| 7 | 344 |
| 8 | -354 |
| 9 | -3304 |
| 10 | -5780 |
| 11 | 9180 |
| 12 | 65258 |
| 13 | 99132 |
| 14 | -226620 |
| 15 | -1313580 |
| 16 | -1690990 |
| 17 | 5441340 |
| 18 | 26681700 |
| 19 | 28070100 |
| 20 | -128211552 |
| 21 | -543818824 |
| 22 | -440381780 |
| 23 | 2978145240 |
| 24 | 11080939914 |
| 25 | 6162798092 |
| 26 | -68377892976 |
| 27 | -225107280388 |
| 28 | -64286124152 |