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 | 3 |
| 2 | 8 |
| 3 | 19 |
| 4 | 41 |
| 5 | 84 |
| 6 | 171 |
| 7 | 347 |
| 8 | 690 |
| 9 | 1385 |
| 10 | 2825 |
| 11 | 5438 |
| 12 | 11077 |
| 13 | 24535 |
| 14 | 33720 |
| 15 | 102623 |
| 16 | 350605 |
| 17 | -1120228 |
| 18 | 5876775 |
| 19 | 11232063 |
| 20 | -256532422 |
| 21 | 1748895117 |
| 22 | -4057110163 |
| 23 | -42841409122 |
| 24 | 605093026361 |
| 25 | -3691581277925 |
| 26 | 3538657621384 |
| 27 | 186391745956155 |
| 28 | -2296017574506751 |