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 | 2 |
| 3 | 5 |
| 4 | 13 |
| 5 | 35 |
| 6 | 100 |
| 7 | 296 |
| 8 | 903 |
| 9 | 2857 |
| 10 | 9274 |
| 11 | 30852 |
| 12 | 104784 |
| 13 | 362108 |
| 14 | 1269324 |
| 15 | 4502624 |
| 16 | 16130539 |
| 17 | 58271303 |
| 18 | 212001890 |
| 19 | 776027286 |
| 20 | 2855731796 |