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 | -3 |
| 5 | 5 |
| 6 | 3 |
| 7 | -30 |
| 8 | 35 |
| 9 | 15 |
| 10 | -70 |
| 11 | 63 |
| 12 | -5 |
| 13 | 105 |
| 14 | -315 |
| 15 | 231 |
| 16 | -35 |
| 17 | 315 |
| 18 | -693 |
| 19 | 429 |
| 20 | 35 |
| 21 | -1260 |
| 22 | 6930 |
| 23 | -12012 |
| 24 | 6435 |
| 25 | 315 |
| 26 | -4620 |
| 27 | 18018 |
| 28 | -25740 |
| 29 | 12155 |
| 30 | -63 |
| 31 | 3465 |
| 32 | -30030 |
| 33 | 90090 |
| 34 | -109395 |
| 35 | 46189 |
| 36 | -693 |
| 37 | 15015 |
| 38 | -90090 |
| 39 | 218790 |
| 40 | -230945 |
| 41 | 88179 |
| 42 | 231 |
| 43 | -18018 |
| 44 | 225225 |
| 45 | -1021020 |
| 46 | 2078505 |
| 47 | -1939938 |
| 48 | 676039 |