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 | 3 |
| 3 | 3 |
| 4 | 2 |
| 5 | 3 |
| 6 | 5 |
| 7 | -4 |
| 8 | 5 |
| 9 | 55 |
| 10 | -212 |
| 11 | 201 |
| 12 | 2381 |
| 13 | -15350 |
| 14 | 35183 |
| 15 | 145359 |
| 16 | -1821438 |
| 17 | 8117231 |
| 18 | -521487 |
| 19 | -278996548 |
| 20 | 2261959961 |
| 21 | -7554900397 |
| 22 | -34727188796 |
| 23 | 690775844605 |
| 24 | -4901767330647 |
| 25 | 10921820177234 |
| 26 | 179314430713387 |
| 27 | -2668801066419061 |
| 28 | 18150518618843778 |