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 | 0 |
| 3 | 2 |
| 4 | -3 |
| 5 | 8 |
| 6 | -16 |
| 7 | 35 |
| 8 | -72 |
| 9 | 150 |
| 10 | -307 |
| 11 | 628 |
| 12 | -1276 |
| 13 | 2587 |
| 14 | -5228 |
| 15 | 10546 |
| 16 | -21235 |
| 17 | 42704 |
| 18 | -85784 |
| 19 | 172179 |
| 20 | -345344 |
| 21 | 692286 |
| 22 | -1387155 |
| 23 | 2778492 |
| 24 | -5563748 |
| 25 | 11138443 |
| 26 | -22294596 |
| 27 | 44617850 |
| 28 | -89282067 |
| 29 | 178639160 |
| 30 | -357399712 |
| 31 | 714995843 |
| 32 | -1430309496 |
| 33 | 2861133222 |
| 34 | -5723098483 |
| 35 | 11447543236 |