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 | -2 |
| 4 | -17 |
| 5 | -57 |
| 6 | -72 |
| 7 | 386 |
| 8 | 3007 |
| 9 | 10239 |
| 10 | 9205 |
| 11 | -111000 |
| 12 | -761932 |
| 13 | -2419388 |
| 14 | -810428 |
| 15 | 36696186 |
| 16 | 223335951 |
| 17 | 638716047 |
| 18 | -268768549 |
| 19 | -12961722498 |
| 20 | -70517888953 |
| 21 | -176288334833 |
| 22 | 256285732480 |
| 23 | 4745735309240 |
| 24 | 23204309443908 |
| 25 | 48765510266948 |
| 26 | -144850760459972 |