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 | 1 |
| 2 | 4 |
| 3 | 6 |
| 4 | 21 |
| 5 | 47 |
| 6 | 134 |
| 7 | 323 |
| 8 | 876 |
| 9 | 2224 |
| 10 | 5885 |
| 11 | 15146 |
| 12 | 39574 |
| 13 | 102250 |
| 14 | 265574 |
| 15 | 686208 |
| 16 | 1775646 |
| 17 | 4583718 |
| 18 | 11835037 |
| 19 | 30515520 |
| 20 | 78652647 |