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 | 0 |
| 3 | 2 |
| 4 | 2 |
| 5 | 12 |
| 6 | 10 |
| 7 | 74 |
| 8 | 72 |
| 9 | 538 |
| 10 | 528 |
| 11 | 4682 |
| 12 | 4668 |
| 13 | 47292 |
| 14 | 47218 |
| 15 | 545820 |
| 16 | 545760 |
| 17 | 7087260 |
| 18 | 7086710 |
| 19 | 102247562 |
| 20 | 102247020 |
| 21 | 1622632496 |
| 22 | 1622627890 |
| 23 | 28091567594 |
| 24 | 28091562840 |
| 25 | 526858348368 |
| 26 | 526858301088 |
| 27 | 10641342969902 |
| 28 | 10641342923148 |
| 29 | 230283190977852 |
| 30 | 230283190431480 |