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 | -63 |
| 3 | 730 |
| 4 | -4159 |
| 5 | 15626 |
| 6 | -45990 |
| 7 | 117650 |
| 8 | -266303 |
| 9 | 532171 |
| 10 | -984438 |
| 11 | 1771562 |
| 12 | -3036070 |
| 13 | 4826810 |
| 14 | -7411950 |
| 15 | 11406980 |
| 16 | -17043519 |
| 17 | 24137570 |
| 18 | -33526773 |
| 19 | 47045882 |
| 20 | -64988534 |
| 21 | 85884500 |
| 22 | -111608406 |
| 23 | 148035890 |
| 24 | -194401190 |
| 25 | 244156251 |
| 26 | -304089030 |
| 27 | 387952660 |
| 28 | -489306350 |
| 29 | 594823322 |
| 30 | -718639740 |
| 31 | 887503682 |