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 | -1 |
| 4 | -5 |
| 5 | 1 |
| 6 | 7 |
| 7 | -1 |
| 8 | -68 |
| 9 | 1 |
| 10 | 1 |
| 11 | -12 |
| 12 | 228 |
| 13 | -1 |
| 14 | -15 |
| 15 | -770 |
| 16 | -1 |
| 17 | 1 |
| 18 | 2460 |
| 19 | -5166 |
| 20 | -1 |
| 21 | -135762627 |
| 22 | 63 |
| 23 | -266 |
| 24 | 5 |
| 25 | 1 |
| 26 | -175 |
| 27 | 27728847 |
| 28 | -1 |
| 29 | -19535516 |
| 30 | -15 |
| 31 | -3 |
| 32 | -11 |
| 33 | 52 |
| 34 | -1 |
| 35 | -9762340 |
| 36 | -77 |
| 37 | -4 |
| 38 | -1812880 |
| 39 | 1 |
| 40 | 5 |
| 41 | -3 |
| 42 | -46129720 |
| 43 | 9 |
| 44 | -3003037440 |