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 | -4 |
| 3 | -23 |
| 4 | -223 |
| 5 | -2767 |
| 6 | -42268 |
| 7 | -759008 |
| 8 | -15672223 |
| 9 | -365639304 |
| 10 | -9512549191 |
| 11 | -273072804420 |
| 12 | -8575012101043 |
| 13 | -292422232720311 |
| 14 | -10762617713743350 |
| 15 | -425245537127322111 |
| 16 | -17953822507629389009 |
| 17 | -806668679245000383731 |