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 | 4 |
| 1 | -1 |
| 2 | 3 |
| 3 | -7 |
| 4 | 15 |
| 5 | -26 |
| 6 | 51 |
| 7 | -99 |
| 8 | 191 |
| 9 | -367 |
| 10 | 708 |
| 11 | -1365 |
| 12 | 2631 |
| 13 | -5071 |
| 14 | 9775 |
| 15 | -18842 |
| 16 | 36319 |
| 17 | -70007 |
| 18 | 134943 |
| 19 | -260111 |
| 20 | 501380 |
| 21 | -966441 |
| 22 | 1862875 |
| 23 | -3590807 |
| 24 | 6921503 |
| 25 | -13341626 |
| 26 | 25716811 |
| 27 | -49570747 |
| 28 | 95550687 |
| 29 | -184179871 |
| 30 | 355018116 |
| 31 | -684319421 |
| 32 | 1319068095 |
| 33 | -2542585503 |
| 34 | 4900991135 |