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 | -4 |
| 2 | 12 |
| 3 | -28 |
| 4 | 60 |
| 5 | -120 |
| 6 | 228 |
| 7 | -416 |
| 8 | 732 |
| 9 | -1252 |
| 10 | 2088 |
| 11 | -3408 |
| 12 | 5460 |
| 13 | -8600 |
| 14 | 13344 |
| 15 | -20424 |
| 16 | 30876 |
| 17 | -46152 |
| 18 | 68268 |
| 19 | -100016 |
| 20 | 145224 |
| 21 | -209120 |
| 22 | 298800 |
| 23 | -423840 |
| 24 | 597108 |
| 25 | -835804 |
| 26 | 1162824 |
| 27 | -1608508 |
| 28 | 2212896 |
| 29 | -3028632 |
| 30 | 4124664 |
| 31 | -5590976 |
| 32 | 7544604 |
| 33 | -10137264 |
| 34 | 13565016 |