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) |
|---|---|
| 1 | 0 |
| 2 | 1 |
| 3 | 7 |
| 4 | 23 |
| 5 | 163 |
| 6 | 71 |
| 7 | 617 |
| 8 | 1479 |
| 9 | 15551 |
| 10 | 17819 |
| 11 | 221209 |
| 12 | 246619 |
| 13 | 3538687 |
| 14 | 3873307 |
| 15 | 4209643 |
| 16 | 9094961 |
| 17 | 166145857 |
| 18 | 59239139 |
| 19 | 1199057081 |
| 20 | 254554945 |
| 21 | 89778475 |
| 22 | 94716499 |
| 23 | 2292289173 |
| 24 | 7218943253 |
| 25 | 189040347533 |