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 | 5 |
| 3 | 19 |
| 4 | 69 |
| 5 | 251 |
| 6 | 923 |
| 7 | 3431 |
| 8 | 12869 |
| 9 | 48619 |
| 10 | 184755 |
| 11 | 705431 |
| 12 | 2704155 |
| 13 | 10400599 |
| 14 | 40116599 |
| 15 | 155117519 |
| 16 | 601080389 |
| 17 | 2333606219 |
| 18 | 9075135299 |
| 19 | 35345263799 |
| 20 | 137846528819 |
| 21 | 538257874439 |
| 22 | 2104098963719 |
| 23 | 8233430727599 |
| 24 | 32247603683099 |
| 25 | 126410606437751 |
| 26 | 495918532948103 |