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 | 3 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 0 |
| 6 | 0 |
| 7 | 0 |
| 8 | 1 |
| 9 | -8 |
| 10 | 36 |
| 11 | -120 |
| 12 | 330 |
| 13 | -792 |
| 14 | 1716 |
| 15 | -3431 |
| 16 | 6420 |
| 17 | -11320 |
| 18 | 18768 |
| 19 | -28764 |
| 20 | 38760 |
| 21 | -38760 |
| 22 | 1 |
| 23 | 149204 |
| 24 | -571780 |
| 25 | 1613128 |
| 26 | -3964050 |
| 27 | 8934120 |
| 28 | -18874260 |
| 29 | 37748521 |
| 30 | -71705864 |
| 31 | 129080160 |
| 32 | -218205280 |
| 33 | 339081224 |
| 34 | -459957168 |
| 35 | 459957168 |
| 36 | 1 |
| 37 | -1749692736 |