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 | 0 |
| 5 | 2 |
| 6 | 1 |
| 7 | 9 |
| 8 | -12 |
| 9 | 6 |
| 10 | 1 |
| 11 | -104 |
| 12 | 204 |
| 13 | -120 |
| 14 | 24 |
| 15 | 1 |
| 16 | 2265 |
| 17 | -4840 |
| 18 | 3540 |
| 19 | -1080 |
| 20 | 120 |
| 21 | 1 |
| 22 | -71064 |
| 23 | 164910 |
| 24 | -138840 |
| 25 | 54360 |
| 26 | -10080 |
| 27 | 720 |
| 28 | 1 |
| 29 | 3079825 |
| 30 | -7626948 |
| 31 | 7134330 |
| 32 | -3300360 |
| 33 | 808920 |
| 34 | -100800 |
| 35 | 5040 |
| 36 | 1 |
| 37 | -176449776 |
| 38 | 460982648 |
| 39 | -468313104 |
| 40 | 244938960 |
| 41 | -72266880 |
| 42 | 12156480 |
| 43 | -1088640 |
| 44 | 40320 |