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 | 4 |
| 3 | 7 |
| 4 | 13 |
| 5 | 23 |
| 6 | 41 |
| 7 | 71 |
| 8 | 121 |
| 9 | 199 |
| 10 | 313 |
| 11 | 455 |
| 12 | 569 |
| 13 | 455 |
| 14 | -455 |
| 15 | -3641 |
| 16 | -12743 |
| 17 | -36409 |
| 18 | -94663 |
| 19 | -233017 |
| 20 | -553415 |
| 21 | -1281593 |
| 22 | -2912711 |
| 23 | -6524473 |
| 24 | -14447047 |
| 25 | -31690297 |
| 26 | -68972999 |
| 27 | -149130809 |
| 28 | -320631239 |
| 29 | -686001721 |
| 30 | -1461481927 |
| 31 | -3101920825 |
| 32 | -6561755591 |
| 33 | -13839339065 |