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 | 9 |
| 2 | 81 |
| 3 | 257 |
| 4 | 791 |
| 5 | 2200 |
| 6 | 6418 |
| 7 | 19041 |
| 8 | 55101 |
| 9 | 160274 |
| 10 | 468839 |
| 11 | 1365913 |
| 12 | 3979457 |
| 13 | 11607265 |
| 14 | 33840611 |
| 15 | 98648082 |
| 16 | 287610828 |
| 17 | 838518475 |
| 18 | 2444629303 |
| 19 | 7127128826 |
| 20 | 20778544998 |
| 21 | 60578554943 |
| 22 | 176612608043 |
| 23 | 514899479923 |
| 24 | 1501152602979 |