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 | 0 |
| 3 | 2 |
| 4 | -1 |
| 5 | -4 |
| 6 | 5 |
| 7 | 2 |
| 8 | -16 |
| 9 | 12 |
| 10 | 27 |
| 11 | -56 |
| 12 | -3 |
| 13 | 140 |
| 14 | -144 |
| 15 | -186 |
| 16 | 547 |
| 17 | -140 |
| 18 | -1175 |
| 19 | 1606 |
| 20 | 1120 |
| 21 | -5096 |
| 22 | 2775 |
| 23 | 9360 |
| 24 | -16807 |
| 25 | -4584 |
| 26 | 45664 |
| 27 | -38070 |
| 28 | -69657 |
| 29 | 167276 |
| 30 | -11347 |
| 31 | -393142 |
| 32 | 450896 |
| 33 | 467108 |
| 34 | -1595725 |
| 35 | 586584 |
| 36 | 3235221 |
| 37 | -4905692 |
| 38 | -2556720 |
| 39 | 14641550 |
| 40 | -9572661 |
| 41 | -25171740 |
| 42 | 50306641 |
| 43 | 6820750 |