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 | 1 |
| 2 | -1 |
| 3 | 1 |
| 4 | -2 |
| 5 | 1 |
| 6 | 1 |
| 7 | -3 |
| 8 | 5 |
| 9 | -3 |
| 10 | 1 |
| 11 | -4 |
| 12 | 14 |
| 13 | -28 |
| 14 | 17 |
| 15 | 1 |
| 16 | -5 |
| 17 | 30 |
| 18 | -126 |
| 19 | 255 |
| 20 | -155 |
| 21 | 1 |
| 22 | -6 |
| 23 | 55 |
| 24 | -396 |
| 25 | 1683 |
| 26 | -3410 |
| 27 | 2073 |
| 28 | 1 |
| 29 | -7 |
| 30 | 91 |
| 31 | -1001 |
| 32 | 7293 |
| 33 | -31031 |
| 34 | 62881 |
| 35 | -38227 |
| 36 | 1 |
| 37 | -8 |
| 38 | 140 |
| 39 | -2184 |
| 40 | 24310 |
| 41 | -177320 |
| 42 | 754572 |
| 43 | -1529080 |
| 44 | 929569 |
| 45 | 1 |
| 46 | -9 |
| 47 | 204 |
| 48 | -4284 |
| 49 | 67626 |
| 50 | -753610 |
| 51 | 5497596 |
| 52 | -23394924 |
| 53 | 47408019 |