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 | 2 |
| 2 | 4 |
| 3 | 10 |
| 4 | 24 |
| 5 | 64 |
| 6 | 184 |
| 7 | 536 |
| 8 | 1608 |
| 9 | 5104 |
| 10 | 16448 |
| 11 | 55136 |
| 12 | 187136 |
| 13 | 658624 |
| 14 | 2339648 |
| 15 | 8618208 |
| 16 | 31884640 |
| 17 | 121733120 |
| 18 | 468209408 |
| 19 | 1849540416 |
| 20 | 7342849216 |