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 | 0 |
| 3 | 1 |
| 4 | -2 |
| 5 | 4 |
| 6 | -7 |
| 7 | 11 |
| 8 | -16 |
| 9 | 23 |
| 10 | -36 |
| 11 | 65 |
| 12 | -129 |
| 13 | 256 |
| 14 | -473 |
| 15 | 772 |
| 16 | -1028 |
| 17 | 835 |
| 18 | 776 |
| 19 | -5755 |
| 20 | 17562 |
| 21 | -41750 |
| 22 | 86678 |
| 23 | -165145 |
| 24 | 299949 |
| 25 | -541837 |
| 26 | 1020029 |
| 27 | -2068203 |
| 28 | 4509512 |
| 29 | -10252952 |
| 30 | 23465297 |
| 31 | -52762788 |
| 32 | 115160832 |
| 33 | -243018459 |
| 34 | 496094524 |
| 35 | -982431070 |
| 36 | 1894710043 |
| 37 | -3574095362 |