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) |
|---|---|
| 1 | 0 |
| 2 | -2 |
| 3 | 1 |
| 4 | -7 |
| 5 | 3 |
| 6 | -21 |
| 7 | 7 |
| 8 | -49 |
| 9 | 23 |
| 10 | -97 |
| 11 | 57 |
| 12 | -195 |
| 13 | 117 |
| 14 | -359 |
| 15 | 256 |
| 16 | -624 |
| 17 | 498 |
| 18 | -1086 |
| 19 | 909 |
| 20 | -1831 |
| 21 | 1634 |
| 22 | -2986 |
| 23 | 2833 |
| 24 | -4847 |
| 25 | 4728 |
| 26 | -7700 |
| 27 | 7798 |
| 28 | -12026 |
| 29 | 12537 |
| 30 | -18633 |
| 31 | 19745 |
| 32 | -28479 |
| 33 | 30723 |
| 34 | -42955 |
| 35 | 47100 |
| 36 | -64284 |
| 37 | 71136 |
| 38 | -95228 |
| 39 | 106402 |
| 40 | -139718 |
| 41 | 157327 |
| 42 | -203495 |