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 | -16 |
| 2 | 104 |
| 3 | -352 |
| 4 | 772 |
| 5 | -2144 |
| 6 | 8032 |
| 7 | -21088 |
| 8 | 41034 |
| 9 | -107728 |
| 10 | 320160 |
| 11 | -703648 |
| 12 | 1435960 |
| 13 | -3611040 |
| 14 | 8707808 |
| 15 | -18347392 |
| 16 | 39248691 |
| 17 | -88070064 |
| 18 | 194779296 |
| 19 | -412179776 |
| 20 | 848638468 |
| 21 | -1802931104 |
| 22 | 3862466240 |
| 23 | -7869949440 |
| 24 | 15883030654 |