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 | -3 |
| 5 | 1 |
| 6 | 1 |
| 7 | -7 |
| 8 | 6 |
| 9 | 0 |
| 10 | 1 |
| 11 | -15 |
| 12 | 25 |
| 13 | 0 |
| 14 | -6 |
| 15 | 1 |
| 16 | -31 |
| 17 | 90 |
| 18 | 0 |
| 19 | -90 |
| 20 | 30 |
| 21 | 1 |
| 22 | -63 |
| 23 | 301 |
| 24 | 0 |
| 25 | -840 |
| 26 | 630 |
| 27 | -90 |
| 28 | 1 |
| 29 | -127 |
| 30 | 966 |
| 31 | 0 |
| 32 | -6300 |
| 33 | 7980 |
| 34 | -2520 |
| 35 | 0 |
| 36 | 1 |
| 37 | -255 |
| 38 | 3025 |
| 39 | 0 |
| 40 | -41706 |
| 41 | 79380 |
| 42 | -41580 |
| 43 | 0 |
| 44 | 2520 |