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 | 1 |
| 4 | 2 |
| 5 | 5 |
| 6 | 12 |
| 7 | 30 |
| 8 | 86 |
| 9 | 253 |
| 10 | 748 |
| 11 | 2274 |
| 12 | 7152 |
| 13 | 22890 |
| 14 | 74189 |
| 15 | 243342 |
| 16 | 808599 |
| 17 | 2716549 |
| 18 | 9213420 |
| 19 | 31498358 |
| 20 | 108483093 |
| 21 | 376145636 |
| 22 | 1312463081 |
| 23 | 4605569378 |
| 24 | 16245866825 |