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 | 1 |
| 3 | 2 |
| 4 | 6 |
| 5 | 12 |
| 6 | 40 |
| 7 | 74 |
| 8 | 300 |
| 9 | 538 |
| 10 | 2598 |
| 11 | 4682 |
| 12 | 25938 |
| 13 | 47292 |
| 14 | 296488 |
| 15 | 545820 |
| 16 | 3816240 |
| 17 | 7087260 |
| 18 | 54666830 |
| 19 | 102247562 |
| 20 | 862437450 |
| 21 | 1622632496 |
| 22 | 14857095400 |
| 23 | 28091567594 |
| 24 | 277474931700 |
| 25 | 526858348368 |
| 26 | 5584100612118 |
| 27 | 10641342969902 |
| 28 | 120462266677578 |