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 | 0 |
| 2 | 1 |
| 3 | 0 |
| 4 | -1 |
| 5 | 2 |
| 6 | 0 |
| 7 | 2 |
| 8 | -6 |
| 9 | 5 |
| 10 | 0 |
| 11 | -5 |
| 12 | 20 |
| 13 | -28 |
| 14 | 14 |
| 15 | 0 |
| 16 | 14 |
| 17 | -70 |
| 18 | 135 |
| 19 | -120 |
| 20 | 42 |
| 21 | 0 |
| 22 | -42 |
| 23 | 252 |
| 24 | -616 |
| 25 | 770 |
| 26 | -495 |
| 27 | 132 |
| 28 | 0 |
| 29 | 132 |
| 30 | -924 |
| 31 | 2730 |
| 32 | -4368 |
| 33 | 4004 |
| 34 | -2002 |
| 35 | 429 |
| 36 | 0 |
| 37 | -429 |
| 38 | 3432 |
| 39 | -11880 |
| 40 | 23100 |
| 41 | -27300 |
| 42 | 19656 |
| 43 | -8008 |
| 44 | 1430 |