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 | 3 |
| 2 | 11 |
| 3 | 43 |
| 4 | 179 |
| 5 | 771 |
| 6 | 3395 |
| 7 | 15171 |
| 8 | 68515 |
| 9 | 311907 |
| 10 | 1428835 |
| 11 | 6578531 |
| 12 | 30414435 |
| 13 | 141105251 |
| 14 | 656588899 |
| 15 | 3063038051 |
| 16 | 14321092195 |
| 17 | 67088405091 |
| 18 | 314825048675 |
| 19 | 1479654425187 |
| 20 | 6963888239203 |
| 21 | 32815960756835 |
| 22 | 154813864252003 |