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 | 3 |
| 4 | -4 |
| 5 | 1 |
| 6 | -25 |
| 7 | 36 |
| 8 | -12 |
| 9 | 1 |
| 10 | 543 |
| 11 | -800 |
| 12 | 288 |
| 13 | -32 |
| 14 | 1 |
| 15 | -29281 |
| 16 | 43440 |
| 17 | -16000 |
| 18 | 1920 |
| 19 | -80 |
| 20 | 1 |
| 21 | 3781503 |
| 22 | -5621952 |
| 23 | 2085120 |
| 24 | -256000 |
| 25 | 11520 |
| 26 | -192 |
| 27 | 1 |
| 28 | -1138779265 |
| 29 | 1694113344 |
| 30 | -629658624 |
| 31 | 77844480 |
| 32 | -3584000 |
| 33 | 64512 |
| 34 | -448 |
| 35 | 1 |
| 36 | 783702329343 |
| 37 | -1166109967360 |
| 38 | 433693016064 |
| 39 | -53730869248 |
| 40 | 2491023360 |
| 41 | -45875200 |
| 42 | 344064 |
| 43 | -1024 |
| 44 | 1 |