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 | 0 |
| 2 | -14 |
| 3 | 0 |
| 4 | 786 |
| 5 | 0 |
| 6 | -61340 |
| 7 | 0 |
| 8 | 5562130 |
| 9 | 0 |
| 10 | -549676764 |
| 11 | 0 |
| 12 | 57440496036 |
| 13 | 0 |
| 14 | -6242164112184 |
| 15 | 0 |
| 16 | 698300344311570 |
| 17 | 0 |
| 18 | -79881547652046140 |
| 19 | 0 |
| 20 | 9301427008157320036 |
| 21 | 0 |
| 22 | -1098786921802152516024 |
| 23 | 0 |
| 24 | 131361675994216221116836 |
| 25 | 0 |
| 26 | -15863471168011822803270200 |
| 27 | 0 |
| 28 | 1932252897656224864335299400 |
| 29 | 0 |
| 30 | -237114404923760858875375113840 |