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 | 2 |
| 2 | 2 |
| 3 | -4 |
| 4 | -28 |
| 5 | -88 |
| 6 | -184 |
| 7 | -208 |
| 8 | 272 |
| 9 | 2336 |
| 10 | 7712 |
| 11 | 16832 |
| 12 | 21056 |
| 13 | -16768 |
| 14 | -193408 |
| 15 | -673024 |
| 16 | -1531648 |
| 17 | -2088448 |
| 18 | 836096 |
| 19 | 15875072 |
| 20 | 58483712 |
| 21 | 138684416 |
| 22 | 203835392 |
| 23 | -16764928 |
| 24 | -1290072064 |
| 25 | -5059698688 |
| 26 | -12498362368 |
| 27 | -19635257344 |
| 28 | -3550855168 |
| 29 | 103608123392 |