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 | 1 |
| 2 | 1 |
| 3 | 7 |
| 4 | 1 |
| 5 | 11 |
| 6 | 25 |
| 7 | 15 |
| 8 | 17 |
| 9 | -11 |
| 10 | 241 |
| 11 | -87 |
| 12 | 217 |
| 13 | -467 |
| 14 | 645 |
| 15 | 707 |
| 16 | -159 |
| 17 | 35 |
| 18 | -1451 |
| 19 | 4067 |
| 20 | -9679 |
| 21 | 17661 |
| 22 | -19755 |
| 23 | 42413 |
| 24 | -55615 |
| 25 | 31061 |
| 26 | -59799 |
| 27 | 28231 |
| 28 | 147841 |
| 29 | -230549 |
| 30 | 473185 |
| 31 | -1013017 |
| 32 | 1656385 |
| 33 | -2771619 |
| 34 | 3637865 |
| 35 | -4581335 |
| 36 | 6366313 |
| 37 | -5062635 |
| 38 | -1059971 |
| 39 | 8699659 |
| 40 | -22821903 |