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 | 2 |
| 3 | -2 |
| 4 | 5 |
| 5 | -8 |
| 6 | 16 |
| 7 | -28 |
| 8 | 53 |
| 9 | -96 |
| 10 | 178 |
| 11 | -326 |
| 12 | 601 |
| 13 | -1104 |
| 14 | 2032 |
| 15 | -3736 |
| 16 | 6873 |
| 17 | -12640 |
| 18 | 23250 |
| 19 | -42762 |
| 20 | 78653 |
| 21 | -144664 |
| 22 | 266080 |
| 23 | -489396 |
| 24 | 900141 |
| 25 | -1655616 |
| 26 | 3045154 |
| 27 | -5600910 |
| 28 | 10301681 |
| 29 | -18947744 |
| 30 | 34850336 |
| 31 | -64099760 |
| 32 | 117897841 |
| 33 | -216847936 |
| 34 | 398845538 |
| 35 | -733591314 |
| 36 | 1349284789 |
| 37 | -2481721640 |