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 | -2 |
| 3 | 2 |
| 4 | 28 |
| 5 | 44 |
| 6 | -464 |
| 7 | -3088 |
| 8 | 1408 |
| 9 | 135872 |
| 10 | 726976 |
| 11 | -2959936 |
| 12 | -67261952 |
| 13 | -293413888 |
| 14 | 3054389248 |
| 15 | 52458520064 |
| 16 | 178569842176 |
| 17 | -3909868400128 |
| 18 | -60465254054912 |
| 19 | -149165881689088 |
| 20 | 6569005278939136 |
| 21 | 98054837101881344 |
| 22 | 158559568611401728 |
| 23 | -14356527387138039808 |