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 | 5 |
| 3 | 14 |
| 4 | 43 |
| 5 | 142 |
| 6 | 494 |
| 7 | 1780 |
| 8 | 6563 |
| 9 | 24566 |
| 10 | 92890 |
| 11 | 353740 |
| 12 | 1354126 |
| 13 | 5204396 |
| 14 | 20066492 |
| 15 | 77575144 |
| 16 | 300572963 |
| 17 | 1166868646 |
| 18 | 4537698722 |
| 19 | 17672894044 |
| 20 | 68923788698 |
| 21 | 269129985796 |
| 22 | 1052051579012 |
| 23 | 4116719558104 |
| 24 | 16123810230158 |
| 25 | 63205319996092 |
| 26 | 247959300028484 |