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 | -4 |
| 4 | 6 |
| 5 | -9 |
| 6 | 16 |
| 7 | -29 |
| 8 | 51 |
| 9 | -89 |
| 10 | 156 |
| 11 | -274 |
| 12 | 481 |
| 13 | -844 |
| 14 | 1481 |
| 15 | -2599 |
| 16 | 4561 |
| 17 | -8004 |
| 18 | 14046 |
| 19 | -24649 |
| 20 | 43256 |
| 21 | -75909 |
| 22 | 133211 |
| 23 | -233769 |
| 24 | 410236 |
| 25 | -719914 |
| 26 | 1263361 |
| 27 | -2217044 |
| 28 | 3890641 |
| 29 | -6827599 |
| 30 | 11981601 |
| 31 | -21026244 |
| 32 | 36898486 |
| 33 | -64752329 |
| 34 | 113632416 |
| 35 | -199410989 |
| 36 | 349941891 |
| 37 | -614105209 |