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 | -744 |
| 2 | 1 |
| 3 | 159768 |
| 4 | -1488 |
| 5 | 1 |
| 6 | -36866976 |
| 7 | 1069956 |
| 8 | -2232 |
| 9 | 1 |
| 10 | 8507424792 |
| 11 | -561444608 |
| 12 | 2533680 |
| 13 | -2976 |
| 14 | 1 |
| 15 | -1963211493744 |
| 16 | 246683410950 |
| 17 | -2028551200 |
| 18 | 4550940 |
| 19 | -3720 |
| 20 | 1 |
| 21 | 453039686271072 |
| 22 | -96687754014528 |
| 23 | 1304194222980 |
| 24 | -4850017536 |
| 25 | 7121736 |
| 26 | -4464 |
| 27 | 1 |