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 | 1 |
| 5 | -5 |
| 6 | 1 |
| 7 | -14 |
| 8 | 9 |
| 9 | 1 |
| 10 | -30 |
| 11 | 89 |
| 12 | 1 |
| 13 | -55 |
| 14 | 439 |
| 15 | -225 |
| 16 | 1 |
| 17 | -91 |
| 18 | 1519 |
| 19 | -3429 |
| 20 | 1 |
| 21 | -140 |
| 22 | 4214 |
| 23 | -24940 |
| 24 | 11025 |
| 25 | 1 |
| 26 | -204 |
| 27 | 10038 |
| 28 | -122156 |
| 29 | 230481 |
| 30 | 1 |
| 31 | -285 |
| 32 | 21378 |
| 33 | -463490 |
| 34 | 2250621 |
| 35 | -893025 |
| 36 | 1 |
| 37 | -385 |
| 38 | 41778 |
| 39 | -1467290 |
| 40 | 14466221 |
| 41 | -23941125 |
| 42 | 1 |
| 43 | -506 |