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 | 1 |
| 2 | 0 |
| 3 | -1 |
| 4 | -2 |
| 5 | 0 |
| 6 | 0 |
| 7 | 0 |
| 8 | -2 |
| 9 | 3 |
| 10 | 11 |
| 11 | 24 |
| 12 | -60 |
| 13 | -16 |
| 14 | 31 |
| 15 | -217 |
| 16 | -1148 |
| 17 | -164 |
| 18 | 132 |
| 19 | 395 |
| 20 | 697 |
| 21 | -191 |
| 22 | -76 |
| 23 | 125664 |
| 24 | -213885 |
| 25 | -171654 |
| 26 | 114902 |
| 27 | 353497 |
| 28 | -388325 |
| 29 | -1738118 |
| 30 | -222898 |
| 31 | 248633 |
| 32 | 382075 |
| 33 | -1637075 |
| 34 | 21100 |
| 35 | 4049068 |
| 36 | -189147708 |
| 37 | -279083383 |
| 38 | 472023163 |
| 39 | -19063401 |
| 40 | -6718578823 |