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 | 4 |
| 2 | -8 |
| 3 | 40 |
| 4 | -152 |
| 5 | 616 |
| 6 | -2456 |
| 7 | 9832 |
| 8 | -39320 |
| 9 | 157288 |
| 10 | -629144 |
| 11 | 2516584 |
| 12 | -10066328 |
| 13 | 40265320 |
| 14 | -161061272 |
| 15 | 644245096 |
| 16 | -2576980376 |
| 17 | 10307921512 |
| 18 | -41231686040 |
| 19 | 164926744168 |
| 20 | -659706976664 |
| 21 | 2638827906664 |
| 22 | -10555311626648 |
| 23 | 42221246506600 |
| 24 | -168884986026392 |