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 | -2 |
| 4 | 2 |
| 5 | -1 |
| 6 | 4 |
| 7 | -1 |
| 8 | 18 |
| 9 | -22 |
| 10 | 12 |
| 11 | -26 |
| 12 | 67 |
| 13 | -86 |
| 14 | 42 |
| 15 | -235 |
| 16 | 432 |
| 17 | -364 |
| 18 | 506 |
| 19 | -868 |
| 20 | 1434 |
| 21 | -2396 |
| 22 | 2225 |
| 23 | -3348 |
| 24 | 10842 |
| 25 | -11822 |
| 26 | 8049 |
| 27 | -24468 |
| 28 | 36662 |
| 29 | -40024 |
| 30 | 69766 |
| 31 | -96052 |
| 32 | 171976 |
| 33 | -278242 |
| 34 | 251886 |
| 35 | -419723 |
| 36 | 885806 |
| 37 | -998468 |
| 38 | 1103660 |
| 39 | -2381042 |
| 40 | 4009539 |
| 41 | -4478416 |
| 42 | 6372514 |
| 43 | -9913690 |