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 | 1 |
| 5 | -3 |
| 6 | 6 |
| 7 | -3 |
| 8 | 1 |
| 9 | 1 |
| 10 | -7 |
| 11 | 28 |
| 12 | -49 |
| 13 | 70 |
| 14 | -49 |
| 15 | 28 |
| 16 | -7 |
| 17 | 1 |
| 18 | 1 |
| 19 | -15 |
| 20 | 120 |
| 21 | -525 |
| 22 | 1820 |
| 23 | -4095 |
| 24 | 8008 |
| 25 | -10725 |
| 26 | 12870 |
| 27 | -10725 |
| 28 | 8008 |
| 29 | -4095 |
| 30 | 1820 |
| 31 | -525 |
| 32 | 120 |
| 33 | -15 |
| 34 | 1 |