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 | 0 |
| 1 | 1 |
| 2 | 0 |
| 3 | -2 |
| 4 | -5 |
| 5 | -4 |
| 6 | 32 |
| 7 | 225 |
| 8 | 794 |
| 9 | 190 |
| 10 | -22291 |
| 11 | -200298 |
| 12 | -920244 |
| 13 | 924223 |
| 14 | 65848880 |
| 15 | 716920754 |
| 16 | 3831260555 |
| 17 | -13147083976 |
| 18 | -575844827780 |
| 19 | -7162425813919 |
| 20 | -40755845041730 |
| 21 | 320194436283162 |
| 22 | 11810647258173653 |
| 23 | 161108090793013130 |
| 24 | 896865861205240824 |
| 25 | -14305712791762925929 |
| 26 | -487306962045115504436 |