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 | 4 |
| 4 | -5 |
| 5 | 1 |
| 6 | 18 |
| 7 | -29 |
| 8 | 12 |
| 9 | -1 |
| 10 | 120 |
| 11 | -218 |
| 12 | 119 |
| 13 | -22 |
| 14 | 1 |
| 15 | 840 |
| 16 | -1814 |
| 17 | 1285 |
| 18 | -345 |
| 19 | 35 |
| 20 | -1 |
| 21 | 7920 |
| 22 | -18144 |
| 23 | 14674 |
| 24 | -5205 |
| 25 | 805 |
| 26 | -51 |
| 27 | 1 |
| 28 | 75600 |
| 29 | -196356 |
| 30 | 185080 |
| 31 | -79219 |
| 32 | 16450 |
| 33 | -1624 |
| 34 | 70 |
| 35 | -1 |
| 36 | 887040 |
| 37 | -2427312 |
| 38 | 2515036 |
| 39 | -1258628 |
| 40 | 324569 |
| 41 | -43568 |
| 42 | 2954 |
| 43 | -92 |
| 44 | 1 |